xref: /netbsd-src/crypto/external/bsd/openssh/dist/misc.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: misc.c,v 1.3 2010/05/10 20:28:05 jnemeth Exp $	*/
2 /* $OpenBSD: misc.c,v 1.71 2009/02/21 19:32:04 tobias Exp $ */
3 /*
4  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
5  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include "includes.h"
29 __RCSID("$NetBSD: misc.c,v 1.3 2010/05/10 20:28:05 jnemeth Exp $");
30 #include <sys/types.h>
31 #include <sys/ioctl.h>
32 #include <sys/socket.h>
33 #include <sys/param.h>
34 
35 #include <net/if.h>
36 #include <net/if_tun.h>
37 #include <netinet/in.h>
38 #include <netinet/tcp.h>
39 
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <netdb.h>
43 #include <paths.h>
44 #include <pwd.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "xmalloc.h"
52 #include "misc.h"
53 #include "log.h"
54 #include "ssh.h"
55 
56 /* remove newline at end of string */
57 char *
58 chop(char *s)
59 {
60 	char *t = s;
61 	while (*t) {
62 		if (*t == '\n' || *t == '\r') {
63 			*t = '\0';
64 			return s;
65 		}
66 		t++;
67 	}
68 	return s;
69 
70 }
71 
72 /* set/unset filedescriptor to non-blocking */
73 int
74 set_nonblock(int fd)
75 {
76 	int val;
77 
78 	val = fcntl(fd, F_GETFL, 0);
79 	if (val < 0) {
80 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
81 		return (-1);
82 	}
83 	if (val & O_NONBLOCK) {
84 		debug3("fd %d is O_NONBLOCK", fd);
85 		return (0);
86 	}
87 	debug2("fd %d setting O_NONBLOCK", fd);
88 	val |= O_NONBLOCK;
89 	if (fcntl(fd, F_SETFL, val) == -1) {
90 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
91 		    strerror(errno));
92 		return (-1);
93 	}
94 	return (0);
95 }
96 
97 int
98 unset_nonblock(int fd)
99 {
100 	int val;
101 
102 	val = fcntl(fd, F_GETFL, 0);
103 	if (val < 0) {
104 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
105 		return (-1);
106 	}
107 	if (!(val & O_NONBLOCK)) {
108 		debug3("fd %d is not O_NONBLOCK", fd);
109 		return (0);
110 	}
111 	debug("fd %d clearing O_NONBLOCK", fd);
112 	val &= ~O_NONBLOCK;
113 	if (fcntl(fd, F_SETFL, val) == -1) {
114 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
115 		    fd, strerror(errno));
116 		return (-1);
117 	}
118 	return (0);
119 }
120 
121 const char *
122 ssh_gai_strerror(int gaierr)
123 {
124 	if (gaierr == EAI_SYSTEM)
125 		return strerror(errno);
126 	return gai_strerror(gaierr);
127 }
128 
129 /* disable nagle on socket */
130 void
131 set_nodelay(int fd)
132 {
133 	int opt;
134 	socklen_t optlen;
135 
136 	optlen = sizeof opt;
137 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
138 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
139 		return;
140 	}
141 	if (opt == 1) {
142 		debug2("fd %d is TCP_NODELAY", fd);
143 		return;
144 	}
145 	opt = 1;
146 	debug2("fd %d setting TCP_NODELAY", fd);
147 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
148 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
149 }
150 
151 /* Characters considered whitespace in strsep calls. */
152 #define WHITESPACE " \t\r\n"
153 #define QUOTE	"\""
154 
155 /* return next token in configuration line */
156 char *
157 strdelim(char **s)
158 {
159 	char *old;
160 	int wspace = 0;
161 
162 	if (*s == NULL)
163 		return NULL;
164 
165 	old = *s;
166 
167 	*s = strpbrk(*s, WHITESPACE QUOTE "=");
168 	if (*s == NULL)
169 		return (old);
170 
171 	if (*s[0] == '\"') {
172 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
173 		/* Find matching quote */
174 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
175 			return (NULL);		/* no matching quote */
176 		} else {
177 			*s[0] = '\0';
178 			return (old);
179 		}
180 	}
181 
182 	/* Allow only one '=' to be skipped */
183 	if (*s[0] == '=')
184 		wspace = 1;
185 	*s[0] = '\0';
186 
187 	/* Skip any extra whitespace after first token */
188 	*s += strspn(*s + 1, WHITESPACE) + 1;
189 	if (*s[0] == '=' && !wspace)
190 		*s += strspn(*s + 1, WHITESPACE) + 1;
191 
192 	return (old);
193 }
194 
195 struct passwd *
196 pwcopy(struct passwd *pw)
197 {
198 	struct passwd *copy = xcalloc(1, sizeof(*copy));
199 
200 	copy->pw_name = xstrdup(pw->pw_name);
201 	copy->pw_passwd = xstrdup(pw->pw_passwd);
202 	copy->pw_gecos = xstrdup(pw->pw_gecos);
203 	copy->pw_uid = pw->pw_uid;
204 	copy->pw_gid = pw->pw_gid;
205 	copy->pw_expire = pw->pw_expire;
206 	copy->pw_change = pw->pw_change;
207 	copy->pw_class = xstrdup(pw->pw_class);
208 	copy->pw_dir = xstrdup(pw->pw_dir);
209 	copy->pw_shell = xstrdup(pw->pw_shell);
210 	return copy;
211 }
212 
213 /*
214  * Convert ASCII string to TCP/IP port number.
215  * Port must be >=0 and <=65535.
216  * Return -1 if invalid.
217  */
218 int
219 a2port(const char *s)
220 {
221 	long long port;
222 	const char *errstr;
223 
224 	port = strtonum(s, 0, 65535, &errstr);
225 	if (errstr != NULL)
226 		return -1;
227 	return (int)port;
228 }
229 
230 int
231 a2tun(const char *s, int *remote)
232 {
233 	const char *errstr = NULL;
234 	char *sp, *ep;
235 	int tun;
236 
237 	if (remote != NULL) {
238 		*remote = SSH_TUNID_ANY;
239 		sp = xstrdup(s);
240 		if ((ep = strchr(sp, ':')) == NULL) {
241 			xfree(sp);
242 			return (a2tun(s, NULL));
243 		}
244 		ep[0] = '\0'; ep++;
245 		*remote = a2tun(ep, NULL);
246 		tun = a2tun(sp, NULL);
247 		xfree(sp);
248 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
249 	}
250 
251 	if (strcasecmp(s, "any") == 0)
252 		return (SSH_TUNID_ANY);
253 
254 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
255 	if (errstr != NULL)
256 		return (SSH_TUNID_ERR);
257 
258 	return (tun);
259 }
260 
261 #define SECONDS		1
262 #define MINUTES		(SECONDS * 60)
263 #define HOURS		(MINUTES * 60)
264 #define DAYS		(HOURS * 24)
265 #define WEEKS		(DAYS * 7)
266 
267 /*
268  * Convert a time string into seconds; format is
269  * a sequence of:
270  *      time[qualifier]
271  *
272  * Valid time qualifiers are:
273  *      <none>  seconds
274  *      s|S     seconds
275  *      m|M     minutes
276  *      h|H     hours
277  *      d|D     days
278  *      w|W     weeks
279  *
280  * Examples:
281  *      90m     90 minutes
282  *      1h30m   90 minutes
283  *      2d      2 days
284  *      1w      1 week
285  *
286  * Return -1 if time string is invalid.
287  */
288 long
289 convtime(const char *s)
290 {
291 	long total, secs;
292 	const char *p;
293 	char *endp;
294 
295 	errno = 0;
296 	total = 0;
297 	p = s;
298 
299 	if (p == NULL || *p == '\0')
300 		return -1;
301 
302 	while (*p) {
303 		secs = strtol(p, &endp, 10);
304 		if (p == endp ||
305 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
306 		    secs < 0)
307 			return -1;
308 
309 		switch (*endp++) {
310 		case '\0':
311 			endp--;
312 			break;
313 		case 's':
314 		case 'S':
315 			break;
316 		case 'm':
317 		case 'M':
318 			secs *= MINUTES;
319 			break;
320 		case 'h':
321 		case 'H':
322 			secs *= HOURS;
323 			break;
324 		case 'd':
325 		case 'D':
326 			secs *= DAYS;
327 			break;
328 		case 'w':
329 		case 'W':
330 			secs *= WEEKS;
331 			break;
332 		default:
333 			return -1;
334 		}
335 		total += secs;
336 		if (total < 0)
337 			return -1;
338 		p = endp;
339 	}
340 
341 	return total;
342 }
343 
344 /*
345  * Returns a standardized host+port identifier string.
346  * Caller must free returned string.
347  */
348 char *
349 put_host_port(const char *host, u_short port)
350 {
351 	char *hoststr;
352 
353 	if (port == 0 || port == SSH_DEFAULT_PORT)
354 		return(xstrdup(host));
355 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
356 		fatal("put_host_port: asprintf: %s", strerror(errno));
357 	debug3("put_host_port: %s", hoststr);
358 	return hoststr;
359 }
360 
361 /*
362  * Search for next delimiter between hostnames/addresses and ports.
363  * Argument may be modified (for termination).
364  * Returns *cp if parsing succeeds.
365  * *cp is set to the start of the next delimiter, if one was found.
366  * If this is the last field, *cp is set to NULL.
367  */
368 char *
369 hpdelim(char **cp)
370 {
371 	char *s, *old;
372 
373 	if (cp == NULL || *cp == NULL)
374 		return NULL;
375 
376 	old = s = *cp;
377 	if (*s == '[') {
378 		if ((s = strchr(s, ']')) == NULL)
379 			return NULL;
380 		else
381 			s++;
382 	} else if ((s = strpbrk(s, ":/")) == NULL)
383 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
384 
385 	switch (*s) {
386 	case '\0':
387 		*cp = NULL;	/* no more fields*/
388 		break;
389 
390 	case ':':
391 	case '/':
392 		*s = '\0';	/* terminate */
393 		*cp = s + 1;
394 		break;
395 
396 	default:
397 		return NULL;
398 	}
399 
400 	return old;
401 }
402 
403 char *
404 cleanhostname(char *host)
405 {
406 	if (*host == '[' && host[strlen(host) - 1] == ']') {
407 		host[strlen(host) - 1] = '\0';
408 		return (host + 1);
409 	} else
410 		return host;
411 }
412 
413 char *
414 colon(char *cp)
415 {
416 	int flag = 0;
417 
418 	if (*cp == ':')		/* Leading colon is part of file name. */
419 		return (0);
420 	if (*cp == '[')
421 		flag = 1;
422 
423 	for (; *cp; ++cp) {
424 		if (*cp == '@' && *(cp+1) == '[')
425 			flag = 1;
426 		if (*cp == ']' && *(cp+1) == ':' && flag)
427 			return (cp+1);
428 		if (*cp == ':' && !flag)
429 			return (cp);
430 		if (*cp == '/')
431 			return (0);
432 	}
433 	return (0);
434 }
435 
436 /* function to assist building execv() arguments */
437 void
438 addargs(arglist *args, char *fmt, ...)
439 {
440 	va_list ap;
441 	char *cp;
442 	u_int nalloc;
443 	int r;
444 
445 	va_start(ap, fmt);
446 	r = vasprintf(&cp, fmt, ap);
447 	va_end(ap);
448 	if (r == -1)
449 		fatal("addargs: argument too long");
450 
451 	nalloc = args->nalloc;
452 	if (args->list == NULL) {
453 		nalloc = 32;
454 		args->num = 0;
455 	} else if (args->num+2 >= nalloc)
456 		nalloc *= 2;
457 
458 	args->list = xrealloc(args->list, nalloc, sizeof(char *));
459 	args->nalloc = nalloc;
460 	args->list[args->num++] = cp;
461 	args->list[args->num] = NULL;
462 }
463 
464 void
465 replacearg(arglist *args, u_int which, char *fmt, ...)
466 {
467 	va_list ap;
468 	char *cp;
469 	int r;
470 
471 	va_start(ap, fmt);
472 	r = vasprintf(&cp, fmt, ap);
473 	va_end(ap);
474 	if (r == -1)
475 		fatal("replacearg: argument too long");
476 
477 	if (which >= args->num)
478 		fatal("replacearg: tried to replace invalid arg %d >= %d",
479 		    which, args->num);
480 	xfree(args->list[which]);
481 	args->list[which] = cp;
482 }
483 
484 void
485 freeargs(arglist *args)
486 {
487 	u_int i;
488 
489 	if (args->list != NULL) {
490 		for (i = 0; i < args->num; i++)
491 			xfree(args->list[i]);
492 		xfree(args->list);
493 		args->nalloc = args->num = 0;
494 		args->list = NULL;
495 	}
496 }
497 
498 /*
499  * Expands tildes in the file name.  Returns data allocated by xmalloc.
500  * Warning: this calls getpw*.
501  */
502 char *
503 tilde_expand_filename(const char *filename, uid_t uid)
504 {
505 	const char *path, *homedir;
506 	char user[128], ret[MAXPATHLEN];
507 	struct passwd *pw;
508 	u_int len, slash;
509 
510 	if (*filename != '~')
511 		return (xstrdup(filename));
512 	filename++;
513 
514 	path = strchr(filename, '/');
515 	if (path != NULL && path > filename) {		/* ~user/path */
516 		slash = path - filename;
517 		if (slash > sizeof(user) - 1)
518 			fatal("tilde_expand_filename: ~username too long");
519 		memcpy(user, filename, slash);
520 		user[slash] = '\0';
521 		if ((pw = getpwnam(user)) == NULL)
522 			fatal("tilde_expand_filename: No such user %s", user);
523 		homedir = pw->pw_dir;
524 	} else {
525 		if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
526 			fatal("tilde_expand_filename: No such uid %ld",
527 			    (long)uid);
528 		homedir = pw->pw_dir;
529 	}
530 
531 	if (strlcpy(ret, homedir, sizeof(ret)) >= sizeof(ret))
532 		fatal("tilde_expand_filename: Path too long");
533 
534 	/* Make sure directory has a trailing '/' */
535 	len = strlen(homedir);
536 	if ((len == 0 || homedir[len - 1] != '/') &&
537 	    strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
538 		fatal("tilde_expand_filename: Path too long");
539 
540 	/* Skip leading '/' from specified path */
541 	if (path != NULL)
542 		filename = path + 1;
543 	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
544 		fatal("tilde_expand_filename: Path too long");
545 
546 	return (xstrdup(ret));
547 }
548 
549 /*
550  * Expand a string with a set of %[char] escapes. A number of escapes may be
551  * specified as (char *escape_chars, char *replacement) pairs. The list must
552  * be terminated by a NULL escape_char. Returns replaced string in memory
553  * allocated by xmalloc.
554  */
555 char *
556 percent_expand(const char *string, ...)
557 {
558 #define EXPAND_MAX_KEYS	16
559 	struct {
560 		const char *key;
561 		const char *repl;
562 	} keys[EXPAND_MAX_KEYS];
563 	u_int num_keys, i, j;
564 	char buf[4096];
565 	va_list ap;
566 
567 	/* Gather keys */
568 	va_start(ap, string);
569 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
570 		keys[num_keys].key = va_arg(ap, char *);
571 		if (keys[num_keys].key == NULL)
572 			break;
573 		keys[num_keys].repl = va_arg(ap, char *);
574 		if (keys[num_keys].repl == NULL)
575 			fatal("percent_expand: NULL replacement");
576 	}
577 	va_end(ap);
578 
579 	if (num_keys >= EXPAND_MAX_KEYS)
580 		fatal("percent_expand: too many keys");
581 
582 	/* Expand string */
583 	*buf = '\0';
584 	for (i = 0; *string != '\0'; string++) {
585 		if (*string != '%') {
586  append:
587 			buf[i++] = *string;
588 			if (i >= sizeof(buf))
589 				fatal("percent_expand: string too long");
590 			buf[i] = '\0';
591 			continue;
592 		}
593 		string++;
594 		if (*string == '%')
595 			goto append;
596 		for (j = 0; j < num_keys; j++) {
597 			if (strchr(keys[j].key, *string) != NULL) {
598 				i = strlcat(buf, keys[j].repl, sizeof(buf));
599 				if (i >= sizeof(buf))
600 					fatal("percent_expand: string too long");
601 				break;
602 			}
603 		}
604 		if (j >= num_keys)
605 			fatal("percent_expand: unknown key %%%c", *string);
606 	}
607 	return (xstrdup(buf));
608 #undef EXPAND_MAX_KEYS
609 }
610 
611 /*
612  * Read an entire line from a public key file into a static buffer, discarding
613  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
614  */
615 int
616 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
617    u_long *lineno)
618 {
619 	while (fgets(buf, bufsz, f) != NULL) {
620 		if (buf[0] == '\0')
621 			continue;
622 		(*lineno)++;
623 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
624 			return 0;
625 		} else {
626 			debug("%s: %s line %lu exceeds size limit", __func__,
627 			    filename, *lineno);
628 			/* discard remainder of line */
629 			while (fgetc(f) != '\n' && !feof(f))
630 				;	/* nothing */
631 		}
632 	}
633 	return -1;
634 }
635 
636 int
637 tun_open(int tun, int mode)
638 {
639 	struct ifreq ifr;
640 	int fd = -1, sock, flag;
641 	const char *tunbase = mode == SSH_TUNMODE_ETHERNET ? "tap" : "tun";
642 
643 	/* Open the tunnel device */
644 	if (tun <= SSH_TUNID_MAX) {
645 		snprintf(ifr.ifr_name, sizeof(ifr.ifr_name),
646 		    "/dev/%s%d", tunbase, tun);
647 		fd = open(ifr.ifr_name, O_RDWR);
648 	} else if (tun == SSH_TUNID_ANY) {
649 		for (tun = 100; tun >= 0; tun--) {
650 			snprintf(ifr.ifr_name, sizeof(ifr.ifr_name),
651 			    "/dev/%s%d", tunbase, tun);
652 			if ((fd = open(ifr.ifr_name, O_RDWR)) >= 0)
653 				break;
654 		}
655 	} else {
656 		debug("%s: invalid tunnel %u", __func__, tun);
657 		return (-1);
658 	}
659 
660 	if (fd < 0) {
661 		debug("%s: %s open failed: %s", __func__, ifr.ifr_name,
662 		    strerror(errno));
663 		return (-1);
664 	}
665 
666 
667 	/* Turn on tunnel headers */
668 	flag = 1;
669 	if (mode != SSH_TUNMODE_ETHERNET &&
670 	    ioctl(fd, TUNSIFHEAD, &flag) == -1) {
671 		debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
672 		    strerror(errno));
673 		close(fd);
674 		return -1;
675 	}
676 
677 	debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
678 	/* Set the tunnel device operation mode */
679 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
680 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
681 		goto failed;
682 
683 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
684 		goto failed;
685 
686 #if 0
687 	/* Set interface mode */
688 	ifr.ifr_flags &= ~IFF_UP;
689 	if (mode == SSH_TUNMODE_ETHERNET)
690 		ifr.ifr_flags |= IFF_LINK0;
691 	else
692 		ifr.ifr_flags &= ~IFF_LINK0;
693 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
694 		goto failed;
695 #endif
696 
697 	/* Bring interface up */
698 	ifr.ifr_flags |= IFF_UP;
699 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
700 		goto failed;
701 
702 	close(sock);
703 	return (fd);
704 
705  failed:
706 	if (fd >= 0)
707 		close(fd);
708 	if (sock >= 0)
709 		close(sock);
710 	debug("%s: failed to set %s mode %d: %s", __func__, ifr.ifr_name,
711 	    mode, strerror(errno));
712 	return (-1);
713 }
714 
715 void
716 sanitise_stdfd(void)
717 {
718 	int nullfd, dupfd;
719 
720 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
721 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
722 		    strerror(errno));
723 		exit(1);
724 	}
725 	while (++dupfd <= 2) {
726 		/* Only clobber closed fds */
727 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
728 			continue;
729 		if (dup2(nullfd, dupfd) == -1) {
730 			fprintf(stderr, "dup2: %s\n", strerror(errno));
731 			exit(1);
732 		}
733 	}
734 	if (nullfd > 2)
735 		close(nullfd);
736 }
737 
738 char *
739 tohex(const void *vp, size_t l)
740 {
741 	const u_char *p = (const u_char *)vp;
742 	char b[3], *r;
743 	size_t i, hl;
744 
745 	if (l > 65536)
746 		return xstrdup("tohex: length > 65536");
747 
748 	hl = l * 2 + 1;
749 	r = xcalloc(1, hl);
750 	for (i = 0; i < l; i++) {
751 		snprintf(b, sizeof(b), "%02x", p[i]);
752 		strlcat(r, b, hl);
753 	}
754 	return (r);
755 }
756 
757 u_int64_t
758 get_u64(const void *vp)
759 {
760 	const u_char *p = (const u_char *)vp;
761 	u_int64_t v;
762 
763 	v  = (u_int64_t)p[0] << 56;
764 	v |= (u_int64_t)p[1] << 48;
765 	v |= (u_int64_t)p[2] << 40;
766 	v |= (u_int64_t)p[3] << 32;
767 	v |= (u_int64_t)p[4] << 24;
768 	v |= (u_int64_t)p[5] << 16;
769 	v |= (u_int64_t)p[6] << 8;
770 	v |= (u_int64_t)p[7];
771 
772 	return (v);
773 }
774 
775 u_int32_t
776 get_u32(const void *vp)
777 {
778 	const u_char *p = (const u_char *)vp;
779 	u_int32_t v;
780 
781 	v  = (u_int32_t)p[0] << 24;
782 	v |= (u_int32_t)p[1] << 16;
783 	v |= (u_int32_t)p[2] << 8;
784 	v |= (u_int32_t)p[3];
785 
786 	return (v);
787 }
788 
789 u_int16_t
790 get_u16(const void *vp)
791 {
792 	const u_char *p = (const u_char *)vp;
793 	u_int16_t v;
794 
795 	v  = (u_int16_t)p[0] << 8;
796 	v |= (u_int16_t)p[1];
797 
798 	return (v);
799 }
800 
801 void
802 put_u64(void *vp, u_int64_t v)
803 {
804 	u_char *p = (u_char *)vp;
805 
806 	p[0] = (u_char)(v >> 56) & 0xff;
807 	p[1] = (u_char)(v >> 48) & 0xff;
808 	p[2] = (u_char)(v >> 40) & 0xff;
809 	p[3] = (u_char)(v >> 32) & 0xff;
810 	p[4] = (u_char)(v >> 24) & 0xff;
811 	p[5] = (u_char)(v >> 16) & 0xff;
812 	p[6] = (u_char)(v >> 8) & 0xff;
813 	p[7] = (u_char)v & 0xff;
814 }
815 
816 void
817 put_u32(void *vp, u_int32_t v)
818 {
819 	u_char *p = (u_char *)vp;
820 
821 	p[0] = (u_char)(v >> 24) & 0xff;
822 	p[1] = (u_char)(v >> 16) & 0xff;
823 	p[2] = (u_char)(v >> 8) & 0xff;
824 	p[3] = (u_char)v & 0xff;
825 }
826 
827 
828 void
829 put_u16(void *vp, u_int16_t v)
830 {
831 	u_char *p = (u_char *)vp;
832 
833 	p[0] = (u_char)(v >> 8) & 0xff;
834 	p[1] = (u_char)v & 0xff;
835 }
836 
837 void
838 ms_subtract_diff(struct timeval *start, int *ms)
839 {
840 	struct timeval diff, finish;
841 
842 	gettimeofday(&finish, NULL);
843 	timersub(&finish, start, &diff);
844 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
845 }
846 
847 void
848 ms_to_timeval(struct timeval *tv, int ms)
849 {
850 	if (ms < 0)
851 		ms = 0;
852 	tv->tv_sec = ms / 1000;
853 	tv->tv_usec = (ms % 1000) * 1000;
854 }
855 
856