xref: /freebsd/crypto/openssh/misc.c (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /* $OpenBSD: misc.c,v 1.92 2013/10/14 23:28:23 djm Exp $ */
2 /* $FreeBSD$ */
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("$FreeBSD$");
30 
31 #include <sys/types.h>
32 #include <sys/ioctl.h>
33 #include <sys/socket.h>
34 #include <sys/param.h>
35 
36 #include <stdarg.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <time.h>
41 #include <unistd.h>
42 
43 #include <netinet/in.h>
44 #include <netinet/in_systm.h>
45 #include <netinet/ip.h>
46 #include <netinet/tcp.h>
47 
48 #include <ctype.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <netdb.h>
52 #ifdef HAVE_PATHS_H
53 # include <paths.h>
54 #include <pwd.h>
55 #endif
56 #ifdef SSH_TUN_OPENBSD
57 #include <net/if.h>
58 #endif
59 
60 #include "xmalloc.h"
61 #include "misc.h"
62 #include "log.h"
63 #include "ssh.h"
64 
65 /* remove newline at end of string */
66 char *
67 chop(char *s)
68 {
69 	char *t = s;
70 	while (*t) {
71 		if (*t == '\n' || *t == '\r') {
72 			*t = '\0';
73 			return s;
74 		}
75 		t++;
76 	}
77 	return s;
78 
79 }
80 
81 /* set/unset filedescriptor to non-blocking */
82 int
83 set_nonblock(int fd)
84 {
85 	int val;
86 
87 	val = fcntl(fd, F_GETFL, 0);
88 	if (val < 0) {
89 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
90 		return (-1);
91 	}
92 	if (val & O_NONBLOCK) {
93 		debug3("fd %d is O_NONBLOCK", fd);
94 		return (0);
95 	}
96 	debug2("fd %d setting O_NONBLOCK", fd);
97 	val |= O_NONBLOCK;
98 	if (fcntl(fd, F_SETFL, val) == -1) {
99 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
100 		    strerror(errno));
101 		return (-1);
102 	}
103 	return (0);
104 }
105 
106 int
107 unset_nonblock(int fd)
108 {
109 	int val;
110 
111 	val = fcntl(fd, F_GETFL, 0);
112 	if (val < 0) {
113 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
114 		return (-1);
115 	}
116 	if (!(val & O_NONBLOCK)) {
117 		debug3("fd %d is not O_NONBLOCK", fd);
118 		return (0);
119 	}
120 	debug("fd %d clearing O_NONBLOCK", fd);
121 	val &= ~O_NONBLOCK;
122 	if (fcntl(fd, F_SETFL, val) == -1) {
123 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
124 		    fd, strerror(errno));
125 		return (-1);
126 	}
127 	return (0);
128 }
129 
130 const char *
131 ssh_gai_strerror(int gaierr)
132 {
133 	if (gaierr == EAI_SYSTEM && errno != 0)
134 		return strerror(errno);
135 	return gai_strerror(gaierr);
136 }
137 
138 /* disable nagle on socket */
139 void
140 set_nodelay(int fd)
141 {
142 	int opt;
143 	socklen_t optlen;
144 
145 	optlen = sizeof opt;
146 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
147 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
148 		return;
149 	}
150 	if (opt == 1) {
151 		debug2("fd %d is TCP_NODELAY", fd);
152 		return;
153 	}
154 	opt = 1;
155 	debug2("fd %d setting TCP_NODELAY", fd);
156 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
157 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
158 }
159 
160 /* Characters considered whitespace in strsep calls. */
161 #define WHITESPACE " \t\r\n"
162 #define QUOTE	"\""
163 
164 /* return next token in configuration line */
165 char *
166 strdelim(char **s)
167 {
168 	char *old;
169 	int wspace = 0;
170 
171 	if (*s == NULL)
172 		return NULL;
173 
174 	old = *s;
175 
176 	*s = strpbrk(*s, WHITESPACE QUOTE "=");
177 	if (*s == NULL)
178 		return (old);
179 
180 	if (*s[0] == '\"') {
181 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
182 		/* Find matching quote */
183 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
184 			return (NULL);		/* no matching quote */
185 		} else {
186 			*s[0] = '\0';
187 			*s += strspn(*s + 1, WHITESPACE) + 1;
188 			return (old);
189 		}
190 	}
191 
192 	/* Allow only one '=' to be skipped */
193 	if (*s[0] == '=')
194 		wspace = 1;
195 	*s[0] = '\0';
196 
197 	/* Skip any extra whitespace after first token */
198 	*s += strspn(*s + 1, WHITESPACE) + 1;
199 	if (*s[0] == '=' && !wspace)
200 		*s += strspn(*s + 1, WHITESPACE) + 1;
201 
202 	return (old);
203 }
204 
205 struct passwd *
206 pwcopy(struct passwd *pw)
207 {
208 	struct passwd *copy = xcalloc(1, sizeof(*copy));
209 
210 	copy->pw_name = xstrdup(pw->pw_name);
211 	copy->pw_passwd = xstrdup(pw->pw_passwd);
212 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
213 	copy->pw_gecos = xstrdup(pw->pw_gecos);
214 #endif
215 	copy->pw_uid = pw->pw_uid;
216 	copy->pw_gid = pw->pw_gid;
217 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
218 	copy->pw_expire = pw->pw_expire;
219 #endif
220 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
221 	copy->pw_change = pw->pw_change;
222 #endif
223 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
224 	copy->pw_class = xstrdup(pw->pw_class);
225 #endif
226 	copy->pw_dir = xstrdup(pw->pw_dir);
227 	copy->pw_shell = xstrdup(pw->pw_shell);
228 	return copy;
229 }
230 
231 /*
232  * Convert ASCII string to TCP/IP port number.
233  * Port must be >=0 and <=65535.
234  * Return -1 if invalid.
235  */
236 int
237 a2port(const char *s)
238 {
239 	long long port;
240 	const char *errstr;
241 
242 	port = strtonum(s, 0, 65535, &errstr);
243 	if (errstr != NULL)
244 		return -1;
245 	return (int)port;
246 }
247 
248 int
249 a2tun(const char *s, int *remote)
250 {
251 	const char *errstr = NULL;
252 	char *sp, *ep;
253 	int tun;
254 
255 	if (remote != NULL) {
256 		*remote = SSH_TUNID_ANY;
257 		sp = xstrdup(s);
258 		if ((ep = strchr(sp, ':')) == NULL) {
259 			free(sp);
260 			return (a2tun(s, NULL));
261 		}
262 		ep[0] = '\0'; ep++;
263 		*remote = a2tun(ep, NULL);
264 		tun = a2tun(sp, NULL);
265 		free(sp);
266 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
267 	}
268 
269 	if (strcasecmp(s, "any") == 0)
270 		return (SSH_TUNID_ANY);
271 
272 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
273 	if (errstr != NULL)
274 		return (SSH_TUNID_ERR);
275 
276 	return (tun);
277 }
278 
279 #define SECONDS		1
280 #define MINUTES		(SECONDS * 60)
281 #define HOURS		(MINUTES * 60)
282 #define DAYS		(HOURS * 24)
283 #define WEEKS		(DAYS * 7)
284 
285 /*
286  * Convert a time string into seconds; format is
287  * a sequence of:
288  *      time[qualifier]
289  *
290  * Valid time qualifiers are:
291  *      <none>  seconds
292  *      s|S     seconds
293  *      m|M     minutes
294  *      h|H     hours
295  *      d|D     days
296  *      w|W     weeks
297  *
298  * Examples:
299  *      90m     90 minutes
300  *      1h30m   90 minutes
301  *      2d      2 days
302  *      1w      1 week
303  *
304  * Return -1 if time string is invalid.
305  */
306 long
307 convtime(const char *s)
308 {
309 	long total, secs;
310 	const char *p;
311 	char *endp;
312 
313 	errno = 0;
314 	total = 0;
315 	p = s;
316 
317 	if (p == NULL || *p == '\0')
318 		return -1;
319 
320 	while (*p) {
321 		secs = strtol(p, &endp, 10);
322 		if (p == endp ||
323 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
324 		    secs < 0)
325 			return -1;
326 
327 		switch (*endp++) {
328 		case '\0':
329 			endp--;
330 			break;
331 		case 's':
332 		case 'S':
333 			break;
334 		case 'm':
335 		case 'M':
336 			secs *= MINUTES;
337 			break;
338 		case 'h':
339 		case 'H':
340 			secs *= HOURS;
341 			break;
342 		case 'd':
343 		case 'D':
344 			secs *= DAYS;
345 			break;
346 		case 'w':
347 		case 'W':
348 			secs *= WEEKS;
349 			break;
350 		default:
351 			return -1;
352 		}
353 		total += secs;
354 		if (total < 0)
355 			return -1;
356 		p = endp;
357 	}
358 
359 	return total;
360 }
361 
362 /*
363  * Returns a standardized host+port identifier string.
364  * Caller must free returned string.
365  */
366 char *
367 put_host_port(const char *host, u_short port)
368 {
369 	char *hoststr;
370 
371 	if (port == 0 || port == SSH_DEFAULT_PORT)
372 		return(xstrdup(host));
373 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
374 		fatal("put_host_port: asprintf: %s", strerror(errno));
375 	debug3("put_host_port: %s", hoststr);
376 	return hoststr;
377 }
378 
379 /*
380  * Search for next delimiter between hostnames/addresses and ports.
381  * Argument may be modified (for termination).
382  * Returns *cp if parsing succeeds.
383  * *cp is set to the start of the next delimiter, if one was found.
384  * If this is the last field, *cp is set to NULL.
385  */
386 char *
387 hpdelim(char **cp)
388 {
389 	char *s, *old;
390 
391 	if (cp == NULL || *cp == NULL)
392 		return NULL;
393 
394 	old = s = *cp;
395 	if (*s == '[') {
396 		if ((s = strchr(s, ']')) == NULL)
397 			return NULL;
398 		else
399 			s++;
400 	} else if ((s = strpbrk(s, ":/")) == NULL)
401 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
402 
403 	switch (*s) {
404 	case '\0':
405 		*cp = NULL;	/* no more fields*/
406 		break;
407 
408 	case ':':
409 	case '/':
410 		*s = '\0';	/* terminate */
411 		*cp = s + 1;
412 		break;
413 
414 	default:
415 		return NULL;
416 	}
417 
418 	return old;
419 }
420 
421 char *
422 cleanhostname(char *host)
423 {
424 	if (*host == '[' && host[strlen(host) - 1] == ']') {
425 		host[strlen(host) - 1] = '\0';
426 		return (host + 1);
427 	} else
428 		return host;
429 }
430 
431 char *
432 colon(char *cp)
433 {
434 	int flag = 0;
435 
436 	if (*cp == ':')		/* Leading colon is part of file name. */
437 		return NULL;
438 	if (*cp == '[')
439 		flag = 1;
440 
441 	for (; *cp; ++cp) {
442 		if (*cp == '@' && *(cp+1) == '[')
443 			flag = 1;
444 		if (*cp == ']' && *(cp+1) == ':' && flag)
445 			return (cp+1);
446 		if (*cp == ':' && !flag)
447 			return (cp);
448 		if (*cp == '/')
449 			return NULL;
450 	}
451 	return NULL;
452 }
453 
454 /* function to assist building execv() arguments */
455 void
456 addargs(arglist *args, char *fmt, ...)
457 {
458 	va_list ap;
459 	char *cp;
460 	u_int nalloc;
461 	int r;
462 
463 	va_start(ap, fmt);
464 	r = vasprintf(&cp, fmt, ap);
465 	va_end(ap);
466 	if (r == -1)
467 		fatal("addargs: argument too long");
468 
469 	nalloc = args->nalloc;
470 	if (args->list == NULL) {
471 		nalloc = 32;
472 		args->num = 0;
473 	} else if (args->num+2 >= nalloc)
474 		nalloc *= 2;
475 
476 	args->list = xrealloc(args->list, nalloc, sizeof(char *));
477 	args->nalloc = nalloc;
478 	args->list[args->num++] = cp;
479 	args->list[args->num] = NULL;
480 }
481 
482 void
483 replacearg(arglist *args, u_int which, char *fmt, ...)
484 {
485 	va_list ap;
486 	char *cp;
487 	int r;
488 
489 	va_start(ap, fmt);
490 	r = vasprintf(&cp, fmt, ap);
491 	va_end(ap);
492 	if (r == -1)
493 		fatal("replacearg: argument too long");
494 
495 	if (which >= args->num)
496 		fatal("replacearg: tried to replace invalid arg %d >= %d",
497 		    which, args->num);
498 	free(args->list[which]);
499 	args->list[which] = cp;
500 }
501 
502 void
503 freeargs(arglist *args)
504 {
505 	u_int i;
506 
507 	if (args->list != NULL) {
508 		for (i = 0; i < args->num; i++)
509 			free(args->list[i]);
510 		free(args->list);
511 		args->nalloc = args->num = 0;
512 		args->list = NULL;
513 	}
514 }
515 
516 /*
517  * Expands tildes in the file name.  Returns data allocated by xmalloc.
518  * Warning: this calls getpw*.
519  */
520 char *
521 tilde_expand_filename(const char *filename, uid_t uid)
522 {
523 	const char *path, *sep;
524 	char user[128], *ret;
525 	struct passwd *pw;
526 	u_int len, slash;
527 
528 	if (*filename != '~')
529 		return (xstrdup(filename));
530 	filename++;
531 
532 	path = strchr(filename, '/');
533 	if (path != NULL && path > filename) {		/* ~user/path */
534 		slash = path - filename;
535 		if (slash > sizeof(user) - 1)
536 			fatal("tilde_expand_filename: ~username too long");
537 		memcpy(user, filename, slash);
538 		user[slash] = '\0';
539 		if ((pw = getpwnam(user)) == NULL)
540 			fatal("tilde_expand_filename: No such user %s", user);
541 	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
542 		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
543 
544 	/* Make sure directory has a trailing '/' */
545 	len = strlen(pw->pw_dir);
546 	if (len == 0 || pw->pw_dir[len - 1] != '/')
547 		sep = "/";
548 	else
549 		sep = "";
550 
551 	/* Skip leading '/' from specified path */
552 	if (path != NULL)
553 		filename = path + 1;
554 
555 	if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= MAXPATHLEN)
556 		fatal("tilde_expand_filename: Path too long");
557 
558 	return (ret);
559 }
560 
561 /*
562  * Expand a string with a set of %[char] escapes. A number of escapes may be
563  * specified as (char *escape_chars, char *replacement) pairs. The list must
564  * be terminated by a NULL escape_char. Returns replaced string in memory
565  * allocated by xmalloc.
566  */
567 char *
568 percent_expand(const char *string, ...)
569 {
570 #define EXPAND_MAX_KEYS	16
571 	u_int num_keys, i, j;
572 	struct {
573 		const char *key;
574 		const char *repl;
575 	} keys[EXPAND_MAX_KEYS];
576 	char buf[4096];
577 	va_list ap;
578 
579 	/* Gather keys */
580 	va_start(ap, string);
581 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
582 		keys[num_keys].key = va_arg(ap, char *);
583 		if (keys[num_keys].key == NULL)
584 			break;
585 		keys[num_keys].repl = va_arg(ap, char *);
586 		if (keys[num_keys].repl == NULL)
587 			fatal("%s: NULL replacement", __func__);
588 	}
589 	if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
590 		fatal("%s: too many keys", __func__);
591 	va_end(ap);
592 
593 	/* Expand string */
594 	*buf = '\0';
595 	for (i = 0; *string != '\0'; string++) {
596 		if (*string != '%') {
597  append:
598 			buf[i++] = *string;
599 			if (i >= sizeof(buf))
600 				fatal("%s: string too long", __func__);
601 			buf[i] = '\0';
602 			continue;
603 		}
604 		string++;
605 		/* %% case */
606 		if (*string == '%')
607 			goto append;
608 		for (j = 0; j < num_keys; j++) {
609 			if (strchr(keys[j].key, *string) != NULL) {
610 				i = strlcat(buf, keys[j].repl, sizeof(buf));
611 				if (i >= sizeof(buf))
612 					fatal("%s: string too long", __func__);
613 				break;
614 			}
615 		}
616 		if (j >= num_keys)
617 			fatal("%s: unknown key %%%c", __func__, *string);
618 	}
619 	return (xstrdup(buf));
620 #undef EXPAND_MAX_KEYS
621 }
622 
623 /*
624  * Read an entire line from a public key file into a static buffer, discarding
625  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
626  */
627 int
628 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
629    u_long *lineno)
630 {
631 	while (fgets(buf, bufsz, f) != NULL) {
632 		if (buf[0] == '\0')
633 			continue;
634 		(*lineno)++;
635 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
636 			return 0;
637 		} else {
638 			debug("%s: %s line %lu exceeds size limit", __func__,
639 			    filename, *lineno);
640 			/* discard remainder of line */
641 			while (fgetc(f) != '\n' && !feof(f))
642 				;	/* nothing */
643 		}
644 	}
645 	return -1;
646 }
647 
648 int
649 tun_open(int tun, int mode)
650 {
651 #if defined(CUSTOM_SYS_TUN_OPEN)
652 	return (sys_tun_open(tun, mode));
653 #elif defined(SSH_TUN_OPENBSD)
654 	struct ifreq ifr;
655 	char name[100];
656 	int fd = -1, sock;
657 
658 	/* Open the tunnel device */
659 	if (tun <= SSH_TUNID_MAX) {
660 		snprintf(name, sizeof(name), "/dev/tun%d", tun);
661 		fd = open(name, O_RDWR);
662 	} else if (tun == SSH_TUNID_ANY) {
663 		for (tun = 100; tun >= 0; tun--) {
664 			snprintf(name, sizeof(name), "/dev/tun%d", tun);
665 			if ((fd = open(name, O_RDWR)) >= 0)
666 				break;
667 		}
668 	} else {
669 		debug("%s: invalid tunnel %u", __func__, tun);
670 		return (-1);
671 	}
672 
673 	if (fd < 0) {
674 		debug("%s: %s open failed: %s", __func__, name, strerror(errno));
675 		return (-1);
676 	}
677 
678 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
679 
680 	/* Set the tunnel device operation mode */
681 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
682 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
683 		goto failed;
684 
685 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
686 		goto failed;
687 
688 	/* Set interface mode */
689 	ifr.ifr_flags &= ~IFF_UP;
690 	if (mode == SSH_TUNMODE_ETHERNET)
691 		ifr.ifr_flags |= IFF_LINK0;
692 	else
693 		ifr.ifr_flags &= ~IFF_LINK0;
694 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
695 		goto failed;
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__, name,
711 	    mode, strerror(errno));
712 	return (-1);
713 #else
714 	error("Tunnel interfaces are not supported on this platform");
715 	return (-1);
716 #endif
717 }
718 
719 void
720 sanitise_stdfd(void)
721 {
722 	int nullfd, dupfd;
723 
724 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
725 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
726 		    strerror(errno));
727 		exit(1);
728 	}
729 	while (++dupfd <= 2) {
730 		/* Only clobber closed fds */
731 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
732 			continue;
733 		if (dup2(nullfd, dupfd) == -1) {
734 			fprintf(stderr, "dup2: %s\n", strerror(errno));
735 			exit(1);
736 		}
737 	}
738 	if (nullfd > 2)
739 		close(nullfd);
740 }
741 
742 char *
743 tohex(const void *vp, size_t l)
744 {
745 	const u_char *p = (const u_char *)vp;
746 	char b[3], *r;
747 	size_t i, hl;
748 
749 	if (l > 65536)
750 		return xstrdup("tohex: length > 65536");
751 
752 	hl = l * 2 + 1;
753 	r = xcalloc(1, hl);
754 	for (i = 0; i < l; i++) {
755 		snprintf(b, sizeof(b), "%02x", p[i]);
756 		strlcat(r, b, hl);
757 	}
758 	return (r);
759 }
760 
761 u_int64_t
762 get_u64(const void *vp)
763 {
764 	const u_char *p = (const u_char *)vp;
765 	u_int64_t v;
766 
767 	v  = (u_int64_t)p[0] << 56;
768 	v |= (u_int64_t)p[1] << 48;
769 	v |= (u_int64_t)p[2] << 40;
770 	v |= (u_int64_t)p[3] << 32;
771 	v |= (u_int64_t)p[4] << 24;
772 	v |= (u_int64_t)p[5] << 16;
773 	v |= (u_int64_t)p[6] << 8;
774 	v |= (u_int64_t)p[7];
775 
776 	return (v);
777 }
778 
779 u_int32_t
780 get_u32(const void *vp)
781 {
782 	const u_char *p = (const u_char *)vp;
783 	u_int32_t v;
784 
785 	v  = (u_int32_t)p[0] << 24;
786 	v |= (u_int32_t)p[1] << 16;
787 	v |= (u_int32_t)p[2] << 8;
788 	v |= (u_int32_t)p[3];
789 
790 	return (v);
791 }
792 
793 u_int16_t
794 get_u16(const void *vp)
795 {
796 	const u_char *p = (const u_char *)vp;
797 	u_int16_t v;
798 
799 	v  = (u_int16_t)p[0] << 8;
800 	v |= (u_int16_t)p[1];
801 
802 	return (v);
803 }
804 
805 void
806 put_u64(void *vp, u_int64_t v)
807 {
808 	u_char *p = (u_char *)vp;
809 
810 	p[0] = (u_char)(v >> 56) & 0xff;
811 	p[1] = (u_char)(v >> 48) & 0xff;
812 	p[2] = (u_char)(v >> 40) & 0xff;
813 	p[3] = (u_char)(v >> 32) & 0xff;
814 	p[4] = (u_char)(v >> 24) & 0xff;
815 	p[5] = (u_char)(v >> 16) & 0xff;
816 	p[6] = (u_char)(v >> 8) & 0xff;
817 	p[7] = (u_char)v & 0xff;
818 }
819 
820 void
821 put_u32(void *vp, u_int32_t v)
822 {
823 	u_char *p = (u_char *)vp;
824 
825 	p[0] = (u_char)(v >> 24) & 0xff;
826 	p[1] = (u_char)(v >> 16) & 0xff;
827 	p[2] = (u_char)(v >> 8) & 0xff;
828 	p[3] = (u_char)v & 0xff;
829 }
830 
831 
832 void
833 put_u16(void *vp, u_int16_t v)
834 {
835 	u_char *p = (u_char *)vp;
836 
837 	p[0] = (u_char)(v >> 8) & 0xff;
838 	p[1] = (u_char)v & 0xff;
839 }
840 
841 void
842 ms_subtract_diff(struct timeval *start, int *ms)
843 {
844 	struct timeval diff, finish;
845 
846 	gettimeofday(&finish, NULL);
847 	timersub(&finish, start, &diff);
848 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
849 }
850 
851 void
852 ms_to_timeval(struct timeval *tv, int ms)
853 {
854 	if (ms < 0)
855 		ms = 0;
856 	tv->tv_sec = ms / 1000;
857 	tv->tv_usec = (ms % 1000) * 1000;
858 }
859 
860 time_t
861 monotime(void)
862 {
863 #if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
864 	struct timespec ts;
865 	static int gettime_failed = 0;
866 
867 	if (!gettime_failed) {
868 		if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
869 			return (ts.tv_sec);
870 		debug3("clock_gettime: %s", strerror(errno));
871 		gettime_failed = 1;
872 	}
873 #endif
874 
875 	return time(NULL);
876 }
877 
878 void
879 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
880 {
881 	bw->buflen = buflen;
882 	bw->rate = kbps;
883 	bw->thresh = bw->rate;
884 	bw->lamt = 0;
885 	timerclear(&bw->bwstart);
886 	timerclear(&bw->bwend);
887 }
888 
889 /* Callback from read/write loop to insert bandwidth-limiting delays */
890 void
891 bandwidth_limit(struct bwlimit *bw, size_t read_len)
892 {
893 	u_int64_t waitlen;
894 	struct timespec ts, rm;
895 
896 	if (!timerisset(&bw->bwstart)) {
897 		gettimeofday(&bw->bwstart, NULL);
898 		return;
899 	}
900 
901 	bw->lamt += read_len;
902 	if (bw->lamt < bw->thresh)
903 		return;
904 
905 	gettimeofday(&bw->bwend, NULL);
906 	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
907 	if (!timerisset(&bw->bwend))
908 		return;
909 
910 	bw->lamt *= 8;
911 	waitlen = (double)1000000L * bw->lamt / bw->rate;
912 
913 	bw->bwstart.tv_sec = waitlen / 1000000L;
914 	bw->bwstart.tv_usec = waitlen % 1000000L;
915 
916 	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
917 		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
918 
919 		/* Adjust the wait time */
920 		if (bw->bwend.tv_sec) {
921 			bw->thresh /= 2;
922 			if (bw->thresh < bw->buflen / 4)
923 				bw->thresh = bw->buflen / 4;
924 		} else if (bw->bwend.tv_usec < 10000) {
925 			bw->thresh *= 2;
926 			if (bw->thresh > bw->buflen * 8)
927 				bw->thresh = bw->buflen * 8;
928 		}
929 
930 		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
931 		while (nanosleep(&ts, &rm) == -1) {
932 			if (errno != EINTR)
933 				break;
934 			ts = rm;
935 		}
936 	}
937 
938 	bw->lamt = 0;
939 	gettimeofday(&bw->bwstart, NULL);
940 }
941 
942 /* Make a template filename for mk[sd]temp() */
943 void
944 mktemp_proto(char *s, size_t len)
945 {
946 	const char *tmpdir;
947 	int r;
948 
949 	if ((tmpdir = getenv("TMPDIR")) != NULL) {
950 		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
951 		if (r > 0 && (size_t)r < len)
952 			return;
953 	}
954 	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
955 	if (r < 0 || (size_t)r >= len)
956 		fatal("%s: template string too short", __func__);
957 }
958 
959 static const struct {
960 	const char *name;
961 	int value;
962 } ipqos[] = {
963 	{ "af11", IPTOS_DSCP_AF11 },
964 	{ "af12", IPTOS_DSCP_AF12 },
965 	{ "af13", IPTOS_DSCP_AF13 },
966 	{ "af21", IPTOS_DSCP_AF21 },
967 	{ "af22", IPTOS_DSCP_AF22 },
968 	{ "af23", IPTOS_DSCP_AF23 },
969 	{ "af31", IPTOS_DSCP_AF31 },
970 	{ "af32", IPTOS_DSCP_AF32 },
971 	{ "af33", IPTOS_DSCP_AF33 },
972 	{ "af41", IPTOS_DSCP_AF41 },
973 	{ "af42", IPTOS_DSCP_AF42 },
974 	{ "af43", IPTOS_DSCP_AF43 },
975 	{ "cs0", IPTOS_DSCP_CS0 },
976 	{ "cs1", IPTOS_DSCP_CS1 },
977 	{ "cs2", IPTOS_DSCP_CS2 },
978 	{ "cs3", IPTOS_DSCP_CS3 },
979 	{ "cs4", IPTOS_DSCP_CS4 },
980 	{ "cs5", IPTOS_DSCP_CS5 },
981 	{ "cs6", IPTOS_DSCP_CS6 },
982 	{ "cs7", IPTOS_DSCP_CS7 },
983 	{ "ef", IPTOS_DSCP_EF },
984 	{ "lowdelay", IPTOS_LOWDELAY },
985 	{ "throughput", IPTOS_THROUGHPUT },
986 	{ "reliability", IPTOS_RELIABILITY },
987 	{ NULL, -1 }
988 };
989 
990 int
991 parse_ipqos(const char *cp)
992 {
993 	u_int i;
994 	char *ep;
995 	long val;
996 
997 	if (cp == NULL)
998 		return -1;
999 	for (i = 0; ipqos[i].name != NULL; i++) {
1000 		if (strcasecmp(cp, ipqos[i].name) == 0)
1001 			return ipqos[i].value;
1002 	}
1003 	/* Try parsing as an integer */
1004 	val = strtol(cp, &ep, 0);
1005 	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1006 		return -1;
1007 	return val;
1008 }
1009 
1010 const char *
1011 iptos2str(int iptos)
1012 {
1013 	int i;
1014 	static char iptos_str[sizeof "0xff"];
1015 
1016 	for (i = 0; ipqos[i].name != NULL; i++) {
1017 		if (ipqos[i].value == iptos)
1018 			return ipqos[i].name;
1019 	}
1020 	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1021 	return iptos_str;
1022 }
1023 
1024 void
1025 lowercase(char *s)
1026 {
1027 	for (; *s; s++)
1028 		*s = tolower((u_char)*s);
1029 }
1030 void
1031 sock_set_v6only(int s)
1032 {
1033 #ifdef IPV6_V6ONLY
1034 	int on = 1;
1035 
1036 	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1037 	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1038 		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1039 #endif
1040 }
1041 
1042 void
1043 sock_get_rcvbuf(int *size, int rcvbuf)
1044 {
1045 	int sock, socksize;
1046 	socklen_t socksizelen = sizeof(socksize);
1047 
1048 	/*
1049 	 * Create a socket but do not connect it.  We use it
1050 	 * only to get the rcv socket size.
1051 	 */
1052 	sock = socket(AF_INET6, SOCK_STREAM, 0);
1053 	if (sock < 0)
1054 		sock = socket(AF_INET, SOCK_STREAM, 0);
1055 	if (sock < 0)
1056 		return;
1057 
1058 	/*
1059 	 * If the tcp_rcv_buf option is set and passed in, attempt to set the
1060 	 *  buffer size to its value.
1061 	 */
1062 	if (rcvbuf)
1063 		setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&rcvbuf,
1064 		    sizeof(rcvbuf));
1065 
1066 	if (getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1067 	    &socksize, &socksizelen) == 0)
1068 		if (size != NULL)
1069 			*size = socksize;
1070 	close(sock);
1071 }
1072