xref: /freebsd/crypto/openssh/misc.c (revision 8ef24a0d4b28fe230e20637f56869cc4148cd2ca)
1 /* $OpenBSD: misc.c,v 1.101 2016/01/20 09:22:39 dtucker 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 "includes.h"
28 
29 #include <sys/types.h>
30 #include <sys/ioctl.h>
31 #include <sys/socket.h>
32 #include <sys/time.h>
33 #include <sys/un.h>
34 
35 #include <limits.h>
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 = xreallocarray(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) >= PATH_MAX)
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 		if (*string == '\0')
609 			fatal("%s: invalid format", __func__);
610 		for (j = 0; j < num_keys; j++) {
611 			if (strchr(keys[j].key, *string) != NULL) {
612 				i = strlcat(buf, keys[j].repl, sizeof(buf));
613 				if (i >= sizeof(buf))
614 					fatal("%s: string too long", __func__);
615 				break;
616 			}
617 		}
618 		if (j >= num_keys)
619 			fatal("%s: unknown key %%%c", __func__, *string);
620 	}
621 	return (xstrdup(buf));
622 #undef EXPAND_MAX_KEYS
623 }
624 
625 /*
626  * Read an entire line from a public key file into a static buffer, discarding
627  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
628  */
629 int
630 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
631    u_long *lineno)
632 {
633 	while (fgets(buf, bufsz, f) != NULL) {
634 		if (buf[0] == '\0')
635 			continue;
636 		(*lineno)++;
637 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
638 			return 0;
639 		} else {
640 			debug("%s: %s line %lu exceeds size limit", __func__,
641 			    filename, *lineno);
642 			/* discard remainder of line */
643 			while (fgetc(f) != '\n' && !feof(f))
644 				;	/* nothing */
645 		}
646 	}
647 	return -1;
648 }
649 
650 int
651 tun_open(int tun, int mode)
652 {
653 #if defined(CUSTOM_SYS_TUN_OPEN)
654 	return (sys_tun_open(tun, mode));
655 #elif defined(SSH_TUN_OPENBSD)
656 	struct ifreq ifr;
657 	char name[100];
658 	int fd = -1, sock;
659 	const char *tunbase = "tun";
660 
661 	if (mode == SSH_TUNMODE_ETHERNET)
662 		tunbase = "tap";
663 
664 	/* Open the tunnel device */
665 	if (tun <= SSH_TUNID_MAX) {
666 		snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
667 		fd = open(name, O_RDWR);
668 	} else if (tun == SSH_TUNID_ANY) {
669 		for (tun = 100; tun >= 0; tun--) {
670 			snprintf(name, sizeof(name), "/dev/%s%d",
671 			    tunbase, tun);
672 			if ((fd = open(name, O_RDWR)) >= 0)
673 				break;
674 		}
675 	} else {
676 		debug("%s: invalid tunnel %u", __func__, tun);
677 		return -1;
678 	}
679 
680 	if (fd < 0) {
681 		debug("%s: %s open: %s", __func__, name, strerror(errno));
682 		return -1;
683 	}
684 
685 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
686 
687 	/* Bring interface up if it is not already */
688 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
689 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
690 		goto failed;
691 
692 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
693 		debug("%s: get interface %s flags: %s", __func__,
694 		    ifr.ifr_name, strerror(errno));
695 		goto failed;
696 	}
697 
698 	if (!(ifr.ifr_flags & IFF_UP)) {
699 		ifr.ifr_flags |= IFF_UP;
700 		if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
701 			debug("%s: activate interface %s: %s", __func__,
702 			    ifr.ifr_name, strerror(errno));
703 			goto failed;
704 		}
705 	}
706 
707 	close(sock);
708 	return fd;
709 
710  failed:
711 	if (fd >= 0)
712 		close(fd);
713 	if (sock >= 0)
714 		close(sock);
715 	return -1;
716 #else
717 	error("Tunnel interfaces are not supported on this platform");
718 	return (-1);
719 #endif
720 }
721 
722 void
723 sanitise_stdfd(void)
724 {
725 	int nullfd, dupfd;
726 
727 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
728 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
729 		    strerror(errno));
730 		exit(1);
731 	}
732 	while (++dupfd <= 2) {
733 		/* Only clobber closed fds */
734 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
735 			continue;
736 		if (dup2(nullfd, dupfd) == -1) {
737 			fprintf(stderr, "dup2: %s\n", strerror(errno));
738 			exit(1);
739 		}
740 	}
741 	if (nullfd > 2)
742 		close(nullfd);
743 }
744 
745 char *
746 tohex(const void *vp, size_t l)
747 {
748 	const u_char *p = (const u_char *)vp;
749 	char b[3], *r;
750 	size_t i, hl;
751 
752 	if (l > 65536)
753 		return xstrdup("tohex: length > 65536");
754 
755 	hl = l * 2 + 1;
756 	r = xcalloc(1, hl);
757 	for (i = 0; i < l; i++) {
758 		snprintf(b, sizeof(b), "%02x", p[i]);
759 		strlcat(r, b, hl);
760 	}
761 	return (r);
762 }
763 
764 u_int64_t
765 get_u64(const void *vp)
766 {
767 	const u_char *p = (const u_char *)vp;
768 	u_int64_t v;
769 
770 	v  = (u_int64_t)p[0] << 56;
771 	v |= (u_int64_t)p[1] << 48;
772 	v |= (u_int64_t)p[2] << 40;
773 	v |= (u_int64_t)p[3] << 32;
774 	v |= (u_int64_t)p[4] << 24;
775 	v |= (u_int64_t)p[5] << 16;
776 	v |= (u_int64_t)p[6] << 8;
777 	v |= (u_int64_t)p[7];
778 
779 	return (v);
780 }
781 
782 u_int32_t
783 get_u32(const void *vp)
784 {
785 	const u_char *p = (const u_char *)vp;
786 	u_int32_t v;
787 
788 	v  = (u_int32_t)p[0] << 24;
789 	v |= (u_int32_t)p[1] << 16;
790 	v |= (u_int32_t)p[2] << 8;
791 	v |= (u_int32_t)p[3];
792 
793 	return (v);
794 }
795 
796 u_int32_t
797 get_u32_le(const void *vp)
798 {
799 	const u_char *p = (const u_char *)vp;
800 	u_int32_t v;
801 
802 	v  = (u_int32_t)p[0];
803 	v |= (u_int32_t)p[1] << 8;
804 	v |= (u_int32_t)p[2] << 16;
805 	v |= (u_int32_t)p[3] << 24;
806 
807 	return (v);
808 }
809 
810 u_int16_t
811 get_u16(const void *vp)
812 {
813 	const u_char *p = (const u_char *)vp;
814 	u_int16_t v;
815 
816 	v  = (u_int16_t)p[0] << 8;
817 	v |= (u_int16_t)p[1];
818 
819 	return (v);
820 }
821 
822 void
823 put_u64(void *vp, u_int64_t v)
824 {
825 	u_char *p = (u_char *)vp;
826 
827 	p[0] = (u_char)(v >> 56) & 0xff;
828 	p[1] = (u_char)(v >> 48) & 0xff;
829 	p[2] = (u_char)(v >> 40) & 0xff;
830 	p[3] = (u_char)(v >> 32) & 0xff;
831 	p[4] = (u_char)(v >> 24) & 0xff;
832 	p[5] = (u_char)(v >> 16) & 0xff;
833 	p[6] = (u_char)(v >> 8) & 0xff;
834 	p[7] = (u_char)v & 0xff;
835 }
836 
837 void
838 put_u32(void *vp, u_int32_t v)
839 {
840 	u_char *p = (u_char *)vp;
841 
842 	p[0] = (u_char)(v >> 24) & 0xff;
843 	p[1] = (u_char)(v >> 16) & 0xff;
844 	p[2] = (u_char)(v >> 8) & 0xff;
845 	p[3] = (u_char)v & 0xff;
846 }
847 
848 void
849 put_u32_le(void *vp, u_int32_t v)
850 {
851 	u_char *p = (u_char *)vp;
852 
853 	p[0] = (u_char)v & 0xff;
854 	p[1] = (u_char)(v >> 8) & 0xff;
855 	p[2] = (u_char)(v >> 16) & 0xff;
856 	p[3] = (u_char)(v >> 24) & 0xff;
857 }
858 
859 void
860 put_u16(void *vp, u_int16_t v)
861 {
862 	u_char *p = (u_char *)vp;
863 
864 	p[0] = (u_char)(v >> 8) & 0xff;
865 	p[1] = (u_char)v & 0xff;
866 }
867 
868 void
869 ms_subtract_diff(struct timeval *start, int *ms)
870 {
871 	struct timeval diff, finish;
872 
873 	gettimeofday(&finish, NULL);
874 	timersub(&finish, start, &diff);
875 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
876 }
877 
878 void
879 ms_to_timeval(struct timeval *tv, int ms)
880 {
881 	if (ms < 0)
882 		ms = 0;
883 	tv->tv_sec = ms / 1000;
884 	tv->tv_usec = (ms % 1000) * 1000;
885 }
886 
887 time_t
888 monotime(void)
889 {
890 #if defined(HAVE_CLOCK_GETTIME) && \
891     (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
892 	struct timespec ts;
893 	static int gettime_failed = 0;
894 
895 	if (!gettime_failed) {
896 #if defined(CLOCK_BOOTTIME)
897 		if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
898 			return (ts.tv_sec);
899 #endif
900 #if defined(CLOCK_MONOTONIC)
901 		if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
902 			return (ts.tv_sec);
903 #endif
904 		debug3("clock_gettime: %s", strerror(errno));
905 		gettime_failed = 1;
906 	}
907 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
908 
909 	return time(NULL);
910 }
911 
912 void
913 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
914 {
915 	bw->buflen = buflen;
916 	bw->rate = kbps;
917 	bw->thresh = bw->rate;
918 	bw->lamt = 0;
919 	timerclear(&bw->bwstart);
920 	timerclear(&bw->bwend);
921 }
922 
923 /* Callback from read/write loop to insert bandwidth-limiting delays */
924 void
925 bandwidth_limit(struct bwlimit *bw, size_t read_len)
926 {
927 	u_int64_t waitlen;
928 	struct timespec ts, rm;
929 
930 	if (!timerisset(&bw->bwstart)) {
931 		gettimeofday(&bw->bwstart, NULL);
932 		return;
933 	}
934 
935 	bw->lamt += read_len;
936 	if (bw->lamt < bw->thresh)
937 		return;
938 
939 	gettimeofday(&bw->bwend, NULL);
940 	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
941 	if (!timerisset(&bw->bwend))
942 		return;
943 
944 	bw->lamt *= 8;
945 	waitlen = (double)1000000L * bw->lamt / bw->rate;
946 
947 	bw->bwstart.tv_sec = waitlen / 1000000L;
948 	bw->bwstart.tv_usec = waitlen % 1000000L;
949 
950 	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
951 		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
952 
953 		/* Adjust the wait time */
954 		if (bw->bwend.tv_sec) {
955 			bw->thresh /= 2;
956 			if (bw->thresh < bw->buflen / 4)
957 				bw->thresh = bw->buflen / 4;
958 		} else if (bw->bwend.tv_usec < 10000) {
959 			bw->thresh *= 2;
960 			if (bw->thresh > bw->buflen * 8)
961 				bw->thresh = bw->buflen * 8;
962 		}
963 
964 		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
965 		while (nanosleep(&ts, &rm) == -1) {
966 			if (errno != EINTR)
967 				break;
968 			ts = rm;
969 		}
970 	}
971 
972 	bw->lamt = 0;
973 	gettimeofday(&bw->bwstart, NULL);
974 }
975 
976 /* Make a template filename for mk[sd]temp() */
977 void
978 mktemp_proto(char *s, size_t len)
979 {
980 	const char *tmpdir;
981 	int r;
982 
983 	if ((tmpdir = getenv("TMPDIR")) != NULL) {
984 		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
985 		if (r > 0 && (size_t)r < len)
986 			return;
987 	}
988 	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
989 	if (r < 0 || (size_t)r >= len)
990 		fatal("%s: template string too short", __func__);
991 }
992 
993 static const struct {
994 	const char *name;
995 	int value;
996 } ipqos[] = {
997 	{ "af11", IPTOS_DSCP_AF11 },
998 	{ "af12", IPTOS_DSCP_AF12 },
999 	{ "af13", IPTOS_DSCP_AF13 },
1000 	{ "af21", IPTOS_DSCP_AF21 },
1001 	{ "af22", IPTOS_DSCP_AF22 },
1002 	{ "af23", IPTOS_DSCP_AF23 },
1003 	{ "af31", IPTOS_DSCP_AF31 },
1004 	{ "af32", IPTOS_DSCP_AF32 },
1005 	{ "af33", IPTOS_DSCP_AF33 },
1006 	{ "af41", IPTOS_DSCP_AF41 },
1007 	{ "af42", IPTOS_DSCP_AF42 },
1008 	{ "af43", IPTOS_DSCP_AF43 },
1009 	{ "cs0", IPTOS_DSCP_CS0 },
1010 	{ "cs1", IPTOS_DSCP_CS1 },
1011 	{ "cs2", IPTOS_DSCP_CS2 },
1012 	{ "cs3", IPTOS_DSCP_CS3 },
1013 	{ "cs4", IPTOS_DSCP_CS4 },
1014 	{ "cs5", IPTOS_DSCP_CS5 },
1015 	{ "cs6", IPTOS_DSCP_CS6 },
1016 	{ "cs7", IPTOS_DSCP_CS7 },
1017 	{ "ef", IPTOS_DSCP_EF },
1018 	{ "lowdelay", IPTOS_LOWDELAY },
1019 	{ "throughput", IPTOS_THROUGHPUT },
1020 	{ "reliability", IPTOS_RELIABILITY },
1021 	{ NULL, -1 }
1022 };
1023 
1024 int
1025 parse_ipqos(const char *cp)
1026 {
1027 	u_int i;
1028 	char *ep;
1029 	long val;
1030 
1031 	if (cp == NULL)
1032 		return -1;
1033 	for (i = 0; ipqos[i].name != NULL; i++) {
1034 		if (strcasecmp(cp, ipqos[i].name) == 0)
1035 			return ipqos[i].value;
1036 	}
1037 	/* Try parsing as an integer */
1038 	val = strtol(cp, &ep, 0);
1039 	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1040 		return -1;
1041 	return val;
1042 }
1043 
1044 const char *
1045 iptos2str(int iptos)
1046 {
1047 	int i;
1048 	static char iptos_str[sizeof "0xff"];
1049 
1050 	for (i = 0; ipqos[i].name != NULL; i++) {
1051 		if (ipqos[i].value == iptos)
1052 			return ipqos[i].name;
1053 	}
1054 	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1055 	return iptos_str;
1056 }
1057 
1058 void
1059 lowercase(char *s)
1060 {
1061 	for (; *s; s++)
1062 		*s = tolower((u_char)*s);
1063 }
1064 
1065 int
1066 unix_listener(const char *path, int backlog, int unlink_first)
1067 {
1068 	struct sockaddr_un sunaddr;
1069 	int saved_errno, sock;
1070 
1071 	memset(&sunaddr, 0, sizeof(sunaddr));
1072 	sunaddr.sun_family = AF_UNIX;
1073 	if (strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1074 		error("%s: \"%s\" too long for Unix domain socket", __func__,
1075 		    path);
1076 		errno = ENAMETOOLONG;
1077 		return -1;
1078 	}
1079 
1080 	sock = socket(PF_UNIX, SOCK_STREAM, 0);
1081 	if (sock < 0) {
1082 		saved_errno = errno;
1083 		error("socket: %.100s", strerror(errno));
1084 		errno = saved_errno;
1085 		return -1;
1086 	}
1087 	if (unlink_first == 1) {
1088 		if (unlink(path) != 0 && errno != ENOENT)
1089 			error("unlink(%s): %.100s", path, strerror(errno));
1090 	}
1091 	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
1092 		saved_errno = errno;
1093 		error("bind: %.100s", strerror(errno));
1094 		close(sock);
1095 		error("%s: cannot bind to path: %s", __func__, path);
1096 		errno = saved_errno;
1097 		return -1;
1098 	}
1099 	if (listen(sock, backlog) < 0) {
1100 		saved_errno = errno;
1101 		error("listen: %.100s", strerror(errno));
1102 		close(sock);
1103 		unlink(path);
1104 		error("%s: cannot listen on path: %s", __func__, path);
1105 		errno = saved_errno;
1106 		return -1;
1107 	}
1108 	return sock;
1109 }
1110 
1111 void
1112 sock_set_v6only(int s)
1113 {
1114 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
1115 	int on = 1;
1116 
1117 	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1118 	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1119 		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1120 #endif
1121 }
1122