1 /* $OpenBSD: misc.c,v 1.96 2015/01/16 06:40:12 deraadt 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/un.h>
33 
34 #include <limits.h>
35 #include <stdarg.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <time.h>
40 #include <unistd.h>
41 
42 #include <netinet/in.h>
43 #include <netinet/in_systm.h>
44 #include <netinet/ip.h>
45 #include <netinet/tcp.h>
46 
47 #include <ctype.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <netdb.h>
51 #ifdef HAVE_PATHS_H
52 # include <paths.h>
53 #include <pwd.h>
54 #endif
55 #ifdef SSH_TUN_OPENBSD
56 #include <net/if.h>
57 #endif
58 
59 #include "xmalloc.h"
60 #include "misc.h"
61 #include "log.h"
62 #include "ssh.h"
63 
64 /* remove newline at end of string */
65 char *
chop(char * s)66 chop(char *s)
67 {
68 	char *t = s;
69 	while (*t) {
70 		if (*t == '\n' || *t == '\r') {
71 			*t = '\0';
72 			return s;
73 		}
74 		t++;
75 	}
76 	return s;
77 
78 }
79 
80 /* set/unset filedescriptor to non-blocking */
81 int
set_nonblock(int fd)82 set_nonblock(int fd)
83 {
84 	int val;
85 
86 	val = fcntl(fd, F_GETFL, 0);
87 	if (val < 0) {
88 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
89 		return (-1);
90 	}
91 	if (val & O_NONBLOCK) {
92 		debug3("fd %d is O_NONBLOCK", fd);
93 		return (0);
94 	}
95 	debug2("fd %d setting O_NONBLOCK", fd);
96 	val |= O_NONBLOCK;
97 	if (fcntl(fd, F_SETFL, val) == -1) {
98 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
99 		    strerror(errno));
100 		return (-1);
101 	}
102 	return (0);
103 }
104 
105 int
unset_nonblock(int fd)106 unset_nonblock(int fd)
107 {
108 	int val;
109 
110 	val = fcntl(fd, F_GETFL, 0);
111 	if (val < 0) {
112 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
113 		return (-1);
114 	}
115 	if (!(val & O_NONBLOCK)) {
116 		debug3("fd %d is not O_NONBLOCK", fd);
117 		return (0);
118 	}
119 	debug("fd %d clearing O_NONBLOCK", fd);
120 	val &= ~O_NONBLOCK;
121 	if (fcntl(fd, F_SETFL, val) == -1) {
122 		debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
123 		    fd, strerror(errno));
124 		return (-1);
125 	}
126 	return (0);
127 }
128 
129 const char *
ssh_gai_strerror(int gaierr)130 ssh_gai_strerror(int gaierr)
131 {
132 	if (gaierr == EAI_SYSTEM && errno != 0)
133 		return strerror(errno);
134 	return gai_strerror(gaierr);
135 }
136 
137 /* disable nagle on socket */
138 void
set_nodelay(int fd)139 set_nodelay(int fd)
140 {
141 	int opt;
142 	socklen_t optlen;
143 
144 	optlen = sizeof opt;
145 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
146 		debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
147 		return;
148 	}
149 	if (opt == 1) {
150 		debug2("fd %d is TCP_NODELAY", fd);
151 		return;
152 	}
153 	opt = 1;
154 	debug2("fd %d setting TCP_NODELAY", fd);
155 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
156 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
157 }
158 
159 /* Characters considered whitespace in strsep calls. */
160 #define WHITESPACE " \t\r\n"
161 #define QUOTE	"\""
162 
163 /* return next token in configuration line */
164 char *
strdelim(char ** s)165 strdelim(char **s)
166 {
167 	char *old;
168 	int wspace = 0;
169 
170 	if (*s == NULL)
171 		return NULL;
172 
173 	old = *s;
174 
175 	*s = strpbrk(*s, WHITESPACE QUOTE "=");
176 	if (*s == NULL)
177 		return (old);
178 
179 	if (*s[0] == '\"') {
180 		memmove(*s, *s + 1, strlen(*s)); /* move nul too */
181 		/* Find matching quote */
182 		if ((*s = strpbrk(*s, QUOTE)) == NULL) {
183 			return (NULL);		/* no matching quote */
184 		} else {
185 			*s[0] = '\0';
186 			*s += strspn(*s + 1, WHITESPACE) + 1;
187 			return (old);
188 		}
189 	}
190 
191 	/* Allow only one '=' to be skipped */
192 	if (*s[0] == '=')
193 		wspace = 1;
194 	*s[0] = '\0';
195 
196 	/* Skip any extra whitespace after first token */
197 	*s += strspn(*s + 1, WHITESPACE) + 1;
198 	if (*s[0] == '=' && !wspace)
199 		*s += strspn(*s + 1, WHITESPACE) + 1;
200 
201 	return (old);
202 }
203 
204 struct passwd *
pwcopy(struct passwd * pw)205 pwcopy(struct passwd *pw)
206 {
207 	struct passwd *copy = xcalloc(1, sizeof(*copy));
208 
209 	copy->pw_name = xstrdup(pw->pw_name);
210 	copy->pw_passwd = pw->pw_passwd ? xstrdup(pw->pw_passwd) : NULL;
211 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
212 	copy->pw_gecos = xstrdup(pw->pw_gecos);
213 #endif
214 	copy->pw_uid = pw->pw_uid;
215 	copy->pw_gid = pw->pw_gid;
216 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
217 	copy->pw_expire = pw->pw_expire;
218 #endif
219 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
220 	copy->pw_change = pw->pw_change;
221 #endif
222 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
223 	copy->pw_class = xstrdup(pw->pw_class);
224 #endif
225 	copy->pw_dir = xstrdup(pw->pw_dir);
226 	copy->pw_shell = xstrdup(pw->pw_shell);
227 	return copy;
228 }
229 
230 /*
231  * Convert ASCII string to TCP/IP port number.
232  * Port must be >=0 and <=65535.
233  * Return -1 if invalid.
234  */
235 int
a2port(const char * s)236 a2port(const char *s)
237 {
238 	long long port;
239 	const char *errstr;
240 
241 	port = strtonum(s, 0, 65535, &errstr);
242 	if (errstr != NULL)
243 		return -1;
244 	return (int)port;
245 }
246 
247 int
a2tun(const char * s,int * remote)248 a2tun(const char *s, int *remote)
249 {
250 	const char *errstr = NULL;
251 	char *sp, *ep;
252 	int tun;
253 
254 	if (remote != NULL) {
255 		*remote = SSH_TUNID_ANY;
256 		sp = xstrdup(s);
257 		if ((ep = strchr(sp, ':')) == NULL) {
258 			free(sp);
259 			return (a2tun(s, NULL));
260 		}
261 		ep[0] = '\0'; ep++;
262 		*remote = a2tun(ep, NULL);
263 		tun = a2tun(sp, NULL);
264 		free(sp);
265 		return (*remote == SSH_TUNID_ERR ? *remote : tun);
266 	}
267 
268 	if (strcasecmp(s, "any") == 0)
269 		return (SSH_TUNID_ANY);
270 
271 	tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
272 	if (errstr != NULL)
273 		return (SSH_TUNID_ERR);
274 
275 	return (tun);
276 }
277 
278 #define SECONDS		1
279 #define MINUTES		(SECONDS * 60)
280 #define HOURS		(MINUTES * 60)
281 #define DAYS		(HOURS * 24)
282 #define WEEKS		(DAYS * 7)
283 
284 /*
285  * Convert a time string into seconds; format is
286  * a sequence of:
287  *      time[qualifier]
288  *
289  * Valid time qualifiers are:
290  *      <none>  seconds
291  *      s|S     seconds
292  *      m|M     minutes
293  *      h|H     hours
294  *      d|D     days
295  *      w|W     weeks
296  *
297  * Examples:
298  *      90m     90 minutes
299  *      1h30m   90 minutes
300  *      2d      2 days
301  *      1w      1 week
302  *
303  * Return -1 if time string is invalid.
304  */
305 long
convtime(const char * s)306 convtime(const char *s)
307 {
308 	long total, secs;
309 	const char *p;
310 	char *endp;
311 
312 	errno = 0;
313 	total = 0;
314 	p = s;
315 
316 	if (p == NULL || *p == '\0')
317 		return -1;
318 
319 	while (*p) {
320 		secs = strtol(p, &endp, 10);
321 		if (p == endp ||
322 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
323 		    secs < 0)
324 			return -1;
325 
326 		switch (*endp++) {
327 		case '\0':
328 			endp--;
329 			break;
330 		case 's':
331 		case 'S':
332 			break;
333 		case 'm':
334 		case 'M':
335 			secs *= MINUTES;
336 			break;
337 		case 'h':
338 		case 'H':
339 			secs *= HOURS;
340 			break;
341 		case 'd':
342 		case 'D':
343 			secs *= DAYS;
344 			break;
345 		case 'w':
346 		case 'W':
347 			secs *= WEEKS;
348 			break;
349 		default:
350 			return -1;
351 		}
352 		total += secs;
353 		if (total < 0)
354 			return -1;
355 		p = endp;
356 	}
357 
358 	return total;
359 }
360 
361 /*
362  * Returns a standardized host+port identifier string.
363  * Caller must free returned string.
364  */
365 char *
put_host_port(const char * host,u_short port)366 put_host_port(const char *host, u_short port)
367 {
368 	char *hoststr;
369 
370 	if (port == 0 || port == SSH_DEFAULT_PORT)
371 		return(xstrdup(host));
372 	if (asprintf(&hoststr, "[%s]:%d", host, (int)port) < 0)
373 		fatal("put_host_port: asprintf: %s", strerror(errno));
374 	debug3("put_host_port: %s", hoststr);
375 	return hoststr;
376 }
377 
378 /*
379  * Search for next delimiter between hostnames/addresses and ports.
380  * Argument may be modified (for termination).
381  * Returns *cp if parsing succeeds.
382  * *cp is set to the start of the next delimiter, if one was found.
383  * If this is the last field, *cp is set to NULL.
384  */
385 char *
hpdelim(char ** cp)386 hpdelim(char **cp)
387 {
388 	char *s, *old;
389 
390 	if (cp == NULL || *cp == NULL)
391 		return NULL;
392 
393 	old = s = *cp;
394 	if (*s == '[') {
395 		if ((s = strchr(s, ']')) == NULL)
396 			return NULL;
397 		else
398 			s++;
399 	} else if ((s = strpbrk(s, ":/")) == NULL)
400 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
401 
402 	switch (*s) {
403 	case '\0':
404 		*cp = NULL;	/* no more fields*/
405 		break;
406 
407 	case ':':
408 	case '/':
409 		*s = '\0';	/* terminate */
410 		*cp = s + 1;
411 		break;
412 
413 	default:
414 		return NULL;
415 	}
416 
417 	return old;
418 }
419 
420 char *
cleanhostname(char * host)421 cleanhostname(char *host)
422 {
423 	if (*host == '[' && host[strlen(host) - 1] == ']') {
424 		host[strlen(host) - 1] = '\0';
425 		return (host + 1);
426 	} else
427 		return host;
428 }
429 
430 char *
colon(char * cp)431 colon(char *cp)
432 {
433 	int flag = 0;
434 
435 	if (*cp == ':')		/* Leading colon is part of file name. */
436 		return NULL;
437 	if (*cp == '[')
438 		flag = 1;
439 
440 	for (; *cp; ++cp) {
441 		if (*cp == '@' && *(cp+1) == '[')
442 			flag = 1;
443 		if (*cp == ']' && *(cp+1) == ':' && flag)
444 			return (cp+1);
445 		if (*cp == ':' && !flag)
446 			return (cp);
447 		if (*cp == '/')
448 			return NULL;
449 	}
450 	return NULL;
451 }
452 
453 /* function to assist building execv() arguments */
454 void
addargs(arglist * args,char * fmt,...)455 addargs(arglist *args, char *fmt, ...)
456 {
457 	va_list ap;
458 	char *cp;
459 	u_int nalloc;
460 	int r;
461 
462 	va_start(ap, fmt);
463 	r = vasprintf(&cp, fmt, ap);
464 	va_end(ap);
465 	if (r == -1)
466 		fatal("addargs: argument too long");
467 
468 	nalloc = args->nalloc;
469 	if (args->list == NULL) {
470 		nalloc = 32;
471 		args->num = 0;
472 	} else if (args->num+2 >= nalloc)
473 		nalloc *= 2;
474 
475 	args->list = xrealloc(args->list, nalloc, sizeof(char *));
476 	args->nalloc = nalloc;
477 	args->list[args->num++] = cp;
478 	args->list[args->num] = NULL;
479 }
480 
481 void
replacearg(arglist * args,u_int which,char * fmt,...)482 replacearg(arglist *args, u_int which, char *fmt, ...)
483 {
484 	va_list ap;
485 	char *cp;
486 	int r;
487 
488 	va_start(ap, fmt);
489 	r = vasprintf(&cp, fmt, ap);
490 	va_end(ap);
491 	if (r == -1)
492 		fatal("replacearg: argument too long");
493 
494 	if (which >= args->num)
495 		fatal("replacearg: tried to replace invalid arg %d >= %d",
496 		    which, args->num);
497 	free(args->list[which]);
498 	args->list[which] = cp;
499 }
500 
501 void
freeargs(arglist * args)502 freeargs(arglist *args)
503 {
504 	u_int i;
505 
506 	if (args->list != NULL) {
507 		for (i = 0; i < args->num; i++)
508 			free(args->list[i]);
509 		free(args->list);
510 		args->nalloc = args->num = 0;
511 		args->list = NULL;
512 	}
513 }
514 
515 /*
516  * Expands tildes in the file name.  Returns data allocated by xmalloc.
517  * Warning: this calls getpw*.
518  */
519 char *
tilde_expand_filename(const char * filename,uid_t uid)520 tilde_expand_filename(const char *filename, uid_t uid)
521 {
522 	const char *path, *sep;
523 	char user[128], *ret;
524 	struct passwd *pw;
525 	u_int len, slash;
526 
527 	if (*filename != '~')
528 		return (xstrdup(filename));
529 	filename++;
530 
531 	path = strchr(filename, '/');
532 	if (path != NULL && path > filename) {		/* ~user/path */
533 		slash = path - filename;
534 		if (slash > sizeof(user) - 1)
535 			fatal("tilde_expand_filename: ~username too long");
536 		memcpy(user, filename, slash);
537 		user[slash] = '\0';
538 		if ((pw = getpwnam(user)) == NULL)
539 			fatal("tilde_expand_filename: No such user %s", user);
540 	} else if ((pw = getpwuid(uid)) == NULL)	/* ~/path */
541 		fatal("tilde_expand_filename: No such uid %ld", (long)uid);
542 
543 	/* Make sure directory has a trailing '/' */
544 	len = strlen(pw->pw_dir);
545 	if (len == 0 || pw->pw_dir[len - 1] != '/')
546 		sep = "/";
547 	else
548 		sep = "";
549 
550 	/* Skip leading '/' from specified path */
551 	if (path != NULL)
552 		filename = path + 1;
553 
554 	if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX)
555 		fatal("tilde_expand_filename: Path too long");
556 
557 	return (ret);
558 }
559 
560 /*
561  * Expand a string with a set of %[char] escapes. A number of escapes may be
562  * specified as (char *escape_chars, char *replacement) pairs. The list must
563  * be terminated by a NULL escape_char. Returns replaced string in memory
564  * allocated by xmalloc.
565  */
566 char *
percent_expand(const char * string,...)567 percent_expand(const char *string, ...)
568 {
569 #define EXPAND_MAX_KEYS	16
570 	u_int num_keys, i, j;
571 	struct {
572 		const char *key;
573 		const char *repl;
574 	} keys[EXPAND_MAX_KEYS];
575 	char buf[4096];
576 	va_list ap;
577 
578 	/* Gather keys */
579 	va_start(ap, string);
580 	for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
581 		keys[num_keys].key = va_arg(ap, char *);
582 		if (keys[num_keys].key == NULL)
583 			break;
584 		keys[num_keys].repl = va_arg(ap, char *);
585 		if (keys[num_keys].repl == NULL)
586 			fatal("%s: NULL replacement", __func__);
587 	}
588 	if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
589 		fatal("%s: too many keys", __func__);
590 	va_end(ap);
591 
592 	/* Expand string */
593 	*buf = '\0';
594 	for (i = 0; *string != '\0'; string++) {
595 		if (*string != '%') {
596  append:
597 			buf[i++] = *string;
598 			if (i >= sizeof(buf))
599 				fatal("%s: string too long", __func__);
600 			buf[i] = '\0';
601 			continue;
602 		}
603 		string++;
604 		/* %% case */
605 		if (*string == '%')
606 			goto append;
607 		for (j = 0; j < num_keys; j++) {
608 			if (strchr(keys[j].key, *string) != NULL) {
609 				i = strlcat(buf, keys[j].repl, sizeof(buf));
610 				if (i >= sizeof(buf))
611 					fatal("%s: string too long", __func__);
612 				break;
613 			}
614 		}
615 		if (j >= num_keys)
616 			fatal("%s: unknown key %%%c", __func__, *string);
617 	}
618 	return (xstrdup(buf));
619 #undef EXPAND_MAX_KEYS
620 }
621 
622 /*
623  * Read an entire line from a public key file into a static buffer, discarding
624  * lines that exceed the buffer size.  Returns 0 on success, -1 on failure.
625  */
626 int
read_keyfile_line(FILE * f,const char * filename,char * buf,size_t bufsz,u_long * lineno)627 read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz,
628    u_long *lineno)
629 {
630 	while (fgets(buf, bufsz, f) != NULL) {
631 		if (buf[0] == '\0')
632 			continue;
633 		(*lineno)++;
634 		if (buf[strlen(buf) - 1] == '\n' || feof(f)) {
635 			return 0;
636 		} else {
637 			debug("%s: %s line %lu exceeds size limit", __func__,
638 			    filename, *lineno);
639 			/* discard remainder of line */
640 			while (fgetc(f) != '\n' && !feof(f))
641 				;	/* nothing */
642 		}
643 	}
644 	return -1;
645 }
646 
647 int
tun_open(int tun,int mode)648 tun_open(int tun, int mode)
649 {
650 #if defined(CUSTOM_SYS_TUN_OPEN)
651 	return (sys_tun_open(tun, mode));
652 #elif defined(SSH_TUN_OPENBSD)
653 	struct ifreq ifr;
654 	char name[100];
655 	int fd = -1, sock;
656 
657 	/* Open the tunnel device */
658 	if (tun <= SSH_TUNID_MAX) {
659 		snprintf(name, sizeof(name), "/dev/tun%d", tun);
660 		fd = open(name, O_RDWR);
661 	} else if (tun == SSH_TUNID_ANY) {
662 		for (tun = 100; tun >= 0; tun--) {
663 			snprintf(name, sizeof(name), "/dev/tun%d", tun);
664 			if ((fd = open(name, O_RDWR)) >= 0)
665 				break;
666 		}
667 	} else {
668 		debug("%s: invalid tunnel %u", __func__, tun);
669 		return (-1);
670 	}
671 
672 	if (fd < 0) {
673 		debug("%s: %s open failed: %s", __func__, name, strerror(errno));
674 		return (-1);
675 	}
676 
677 	debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
678 
679 	/* Set the tunnel device operation mode */
680 	snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
681 	if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
682 		goto failed;
683 
684 	if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
685 		goto failed;
686 
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 
696 	/* Bring interface up */
697 	ifr.ifr_flags |= IFF_UP;
698 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
699 		goto failed;
700 
701 	close(sock);
702 	return (fd);
703 
704  failed:
705 	if (fd >= 0)
706 		close(fd);
707 	if (sock >= 0)
708 		close(sock);
709 	debug("%s: failed to set %s mode %d: %s", __func__, name,
710 	    mode, strerror(errno));
711 	return (-1);
712 #else
713 	error("Tunnel interfaces are not supported on this platform");
714 	return (-1);
715 #endif
716 }
717 
718 void
sanitise_stdfd(void)719 sanitise_stdfd(void)
720 {
721 	int nullfd, dupfd;
722 
723 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
724 		fprintf(stderr, "Couldn't open /dev/null: %s\n",
725 		    strerror(errno));
726 		exit(1);
727 	}
728 	while (++dupfd <= 2) {
729 		/* Only clobber closed fds */
730 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
731 			continue;
732 		if (dup2(nullfd, dupfd) == -1) {
733 			fprintf(stderr, "dup2: %s\n", strerror(errno));
734 			exit(1);
735 		}
736 	}
737 	if (nullfd > 2)
738 		close(nullfd);
739 }
740 
741 char *
tohex(const void * vp,size_t l)742 tohex(const void *vp, size_t l)
743 {
744 	const u_char *p = (const u_char *)vp;
745 	char b[3], *r;
746 	size_t i, hl;
747 
748 	if (l > 65536)
749 		return xstrdup("tohex: length > 65536");
750 
751 	hl = l * 2 + 1;
752 	r = xcalloc(1, hl);
753 	for (i = 0; i < l; i++) {
754 		snprintf(b, sizeof(b), "%02x", p[i]);
755 		strlcat(r, b, hl);
756 	}
757 	return (r);
758 }
759 
760 u_int64_t
get_u64(const void * vp)761 get_u64(const void *vp)
762 {
763 	const u_char *p = (const u_char *)vp;
764 	u_int64_t v;
765 
766 	v  = (u_int64_t)p[0] << 56;
767 	v |= (u_int64_t)p[1] << 48;
768 	v |= (u_int64_t)p[2] << 40;
769 	v |= (u_int64_t)p[3] << 32;
770 	v |= (u_int64_t)p[4] << 24;
771 	v |= (u_int64_t)p[5] << 16;
772 	v |= (u_int64_t)p[6] << 8;
773 	v |= (u_int64_t)p[7];
774 
775 	return (v);
776 }
777 
778 u_int32_t
get_u32(const void * vp)779 get_u32(const void *vp)
780 {
781 	const u_char *p = (const u_char *)vp;
782 	u_int32_t v;
783 
784 	v  = (u_int32_t)p[0] << 24;
785 	v |= (u_int32_t)p[1] << 16;
786 	v |= (u_int32_t)p[2] << 8;
787 	v |= (u_int32_t)p[3];
788 
789 	return (v);
790 }
791 
792 u_int32_t
get_u32_le(const void * vp)793 get_u32_le(const void *vp)
794 {
795 	const u_char *p = (const u_char *)vp;
796 	u_int32_t v;
797 
798 	v  = (u_int32_t)p[0];
799 	v |= (u_int32_t)p[1] << 8;
800 	v |= (u_int32_t)p[2] << 16;
801 	v |= (u_int32_t)p[3] << 24;
802 
803 	return (v);
804 }
805 
806 u_int16_t
get_u16(const void * vp)807 get_u16(const void *vp)
808 {
809 	const u_char *p = (const u_char *)vp;
810 	u_int16_t v;
811 
812 	v  = (u_int16_t)p[0] << 8;
813 	v |= (u_int16_t)p[1];
814 
815 	return (v);
816 }
817 
818 void
put_u64(void * vp,u_int64_t v)819 put_u64(void *vp, u_int64_t v)
820 {
821 	u_char *p = (u_char *)vp;
822 
823 	p[0] = (u_char)(v >> 56) & 0xff;
824 	p[1] = (u_char)(v >> 48) & 0xff;
825 	p[2] = (u_char)(v >> 40) & 0xff;
826 	p[3] = (u_char)(v >> 32) & 0xff;
827 	p[4] = (u_char)(v >> 24) & 0xff;
828 	p[5] = (u_char)(v >> 16) & 0xff;
829 	p[6] = (u_char)(v >> 8) & 0xff;
830 	p[7] = (u_char)v & 0xff;
831 }
832 
833 void
put_u32(void * vp,u_int32_t v)834 put_u32(void *vp, u_int32_t v)
835 {
836 	u_char *p = (u_char *)vp;
837 
838 	p[0] = (u_char)(v >> 24) & 0xff;
839 	p[1] = (u_char)(v >> 16) & 0xff;
840 	p[2] = (u_char)(v >> 8) & 0xff;
841 	p[3] = (u_char)v & 0xff;
842 }
843 
844 void
put_u32_le(void * vp,u_int32_t v)845 put_u32_le(void *vp, u_int32_t v)
846 {
847 	u_char *p = (u_char *)vp;
848 
849 	p[0] = (u_char)v & 0xff;
850 	p[1] = (u_char)(v >> 8) & 0xff;
851 	p[2] = (u_char)(v >> 16) & 0xff;
852 	p[3] = (u_char)(v >> 24) & 0xff;
853 }
854 
855 void
put_u16(void * vp,u_int16_t v)856 put_u16(void *vp, u_int16_t v)
857 {
858 	u_char *p = (u_char *)vp;
859 
860 	p[0] = (u_char)(v >> 8) & 0xff;
861 	p[1] = (u_char)v & 0xff;
862 }
863 
864 void
ms_subtract_diff(struct timeval * start,int * ms)865 ms_subtract_diff(struct timeval *start, int *ms)
866 {
867 	struct timeval diff, finish;
868 
869 	gettimeofday(&finish, NULL);
870 	timersub(&finish, start, &diff);
871 	*ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
872 }
873 
874 void
ms_to_timeval(struct timeval * tv,int ms)875 ms_to_timeval(struct timeval *tv, int ms)
876 {
877 	if (ms < 0)
878 		ms = 0;
879 	tv->tv_sec = ms / 1000;
880 	tv->tv_usec = (ms % 1000) * 1000;
881 }
882 
883 time_t
monotime(void)884 monotime(void)
885 {
886 #if defined(HAVE_CLOCK_GETTIME) && \
887     (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
888 	struct timespec ts;
889 	static int gettime_failed = 0;
890 
891 	if (!gettime_failed) {
892 #if defined(CLOCK_BOOTTIME)
893 		if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
894 			return (ts.tv_sec);
895 #endif
896 #if defined(CLOCK_MONOTONIC)
897 		if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
898 			return (ts.tv_sec);
899 #endif
900 		debug3("clock_gettime: %s", strerror(errno));
901 		gettime_failed = 1;
902 	}
903 #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
904 
905 	return time(NULL);
906 }
907 
908 void
bandwidth_limit_init(struct bwlimit * bw,u_int64_t kbps,size_t buflen)909 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
910 {
911 	bw->buflen = buflen;
912 	bw->rate = kbps;
913 	bw->thresh = bw->rate;
914 	bw->lamt = 0;
915 	timerclear(&bw->bwstart);
916 	timerclear(&bw->bwend);
917 }
918 
919 /* Callback from read/write loop to insert bandwidth-limiting delays */
920 void
bandwidth_limit(struct bwlimit * bw,size_t read_len)921 bandwidth_limit(struct bwlimit *bw, size_t read_len)
922 {
923 	u_int64_t waitlen;
924 	struct timespec ts, rm;
925 
926 	if (!timerisset(&bw->bwstart)) {
927 		gettimeofday(&bw->bwstart, NULL);
928 		return;
929 	}
930 
931 	bw->lamt += read_len;
932 	if (bw->lamt < bw->thresh)
933 		return;
934 
935 	gettimeofday(&bw->bwend, NULL);
936 	timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
937 	if (!timerisset(&bw->bwend))
938 		return;
939 
940 	bw->lamt *= 8;
941 	waitlen = (double)1000000L * bw->lamt / bw->rate;
942 
943 	bw->bwstart.tv_sec = waitlen / 1000000L;
944 	bw->bwstart.tv_usec = waitlen % 1000000L;
945 
946 	if (timercmp(&bw->bwstart, &bw->bwend, >)) {
947 		timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
948 
949 		/* Adjust the wait time */
950 		if (bw->bwend.tv_sec) {
951 			bw->thresh /= 2;
952 			if (bw->thresh < bw->buflen / 4)
953 				bw->thresh = bw->buflen / 4;
954 		} else if (bw->bwend.tv_usec < 10000) {
955 			bw->thresh *= 2;
956 			if (bw->thresh > bw->buflen * 8)
957 				bw->thresh = bw->buflen * 8;
958 		}
959 
960 		TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
961 		while (nanosleep(&ts, &rm) == -1) {
962 			if (errno != EINTR)
963 				break;
964 			ts = rm;
965 		}
966 	}
967 
968 	bw->lamt = 0;
969 	gettimeofday(&bw->bwstart, NULL);
970 }
971 
972 /* Make a template filename for mk[sd]temp() */
973 void
mktemp_proto(char * s,size_t len)974 mktemp_proto(char *s, size_t len)
975 {
976 	const char *tmpdir;
977 	int r;
978 
979 	if ((tmpdir = getenv("TMPDIR")) != NULL) {
980 		r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
981 		if (r > 0 && (size_t)r < len)
982 			return;
983 	}
984 	r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
985 	if (r < 0 || (size_t)r >= len)
986 		fatal("%s: template string too short", __func__);
987 }
988 
989 static const struct {
990 	const char *name;
991 	int value;
992 } ipqos[] = {
993 	{ "af11", IPTOS_DSCP_AF11 },
994 	{ "af12", IPTOS_DSCP_AF12 },
995 	{ "af13", IPTOS_DSCP_AF13 },
996 	{ "af21", IPTOS_DSCP_AF21 },
997 	{ "af22", IPTOS_DSCP_AF22 },
998 	{ "af23", IPTOS_DSCP_AF23 },
999 	{ "af31", IPTOS_DSCP_AF31 },
1000 	{ "af32", IPTOS_DSCP_AF32 },
1001 	{ "af33", IPTOS_DSCP_AF33 },
1002 	{ "af41", IPTOS_DSCP_AF41 },
1003 	{ "af42", IPTOS_DSCP_AF42 },
1004 	{ "af43", IPTOS_DSCP_AF43 },
1005 	{ "cs0", IPTOS_DSCP_CS0 },
1006 	{ "cs1", IPTOS_DSCP_CS1 },
1007 	{ "cs2", IPTOS_DSCP_CS2 },
1008 	{ "cs3", IPTOS_DSCP_CS3 },
1009 	{ "cs4", IPTOS_DSCP_CS4 },
1010 	{ "cs5", IPTOS_DSCP_CS5 },
1011 	{ "cs6", IPTOS_DSCP_CS6 },
1012 	{ "cs7", IPTOS_DSCP_CS7 },
1013 	{ "ef", IPTOS_DSCP_EF },
1014 	{ "lowdelay", IPTOS_LOWDELAY },
1015 	{ "throughput", IPTOS_THROUGHPUT },
1016 	{ "reliability", IPTOS_RELIABILITY },
1017 	{ NULL, -1 }
1018 };
1019 
1020 int
parse_ipqos(const char * cp)1021 parse_ipqos(const char *cp)
1022 {
1023 	u_int i;
1024 	char *ep;
1025 	long val;
1026 
1027 	if (cp == NULL)
1028 		return -1;
1029 	for (i = 0; ipqos[i].name != NULL; i++) {
1030 		if (strcasecmp(cp, ipqos[i].name) == 0)
1031 			return ipqos[i].value;
1032 	}
1033 	/* Try parsing as an integer */
1034 	val = strtol(cp, &ep, 0);
1035 	if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1036 		return -1;
1037 	return val;
1038 }
1039 
1040 const char *
iptos2str(int iptos)1041 iptos2str(int iptos)
1042 {
1043 	int i;
1044 	static char iptos_str[sizeof "0xff"];
1045 
1046 	for (i = 0; ipqos[i].name != NULL; i++) {
1047 		if (ipqos[i].value == iptos)
1048 			return ipqos[i].name;
1049 	}
1050 	snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1051 	return iptos_str;
1052 }
1053 
1054 void
lowercase(char * s)1055 lowercase(char *s)
1056 {
1057 	for (; *s; s++)
1058 		*s = tolower((u_char)*s);
1059 }
1060 
1061 int
unix_listener(const char * path,int backlog,int unlink_first)1062 unix_listener(const char *path, int backlog, int unlink_first)
1063 {
1064 	struct sockaddr_un sunaddr;
1065 	int saved_errno, sock;
1066 
1067 	memset(&sunaddr, 0, sizeof(sunaddr));
1068 	sunaddr.sun_family = AF_UNIX;
1069 	if (strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1070 		error("%s: \"%s\" too long for Unix domain socket", __func__,
1071 		    path);
1072 		errno = ENAMETOOLONG;
1073 		return -1;
1074 	}
1075 
1076 	sock = socket(PF_UNIX, SOCK_STREAM, 0);
1077 	if (sock < 0) {
1078 		saved_errno = errno;
1079 		error("socket: %.100s", strerror(errno));
1080 		errno = saved_errno;
1081 		return -1;
1082 	}
1083 	if (unlink_first == 1) {
1084 		if (unlink(path) != 0 && errno != ENOENT)
1085 			error("unlink(%s): %.100s", path, strerror(errno));
1086 	}
1087 	if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
1088 		saved_errno = errno;
1089 		error("bind: %.100s", strerror(errno));
1090 		close(sock);
1091 		error("%s: cannot bind to path: %s", __func__, path);
1092 		errno = saved_errno;
1093 		return -1;
1094 	}
1095 	if (listen(sock, backlog) < 0) {
1096 		saved_errno = errno;
1097 		error("listen: %.100s", strerror(errno));
1098 		close(sock);
1099 		unlink(path);
1100 		error("%s: cannot listen on path: %s", __func__, path);
1101 		errno = saved_errno;
1102 		return -1;
1103 	}
1104 	return sock;
1105 }
1106 
1107 void
sock_set_v6only(int s)1108 sock_set_v6only(int s)
1109 {
1110 #ifdef IPV6_V6ONLY
1111 	int on = 1;
1112 
1113 	debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1114 	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1115 		error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1116 #endif
1117 }
1118