xref: /titanic_41/usr/src/cmd/ssh/libssh/common/misc.c (revision e4b86885570d77af552e9cf94f142f4d744fb8c8)
1 /*
2  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */
24 /*
25  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #include "includes.h"
30 RCSID("$OpenBSD: misc.c,v 1.19 2002/03/04 17:27:39 stevesk Exp $");
31 
32 #pragma ident	"%Z%%M%	%I%	%E% SMI"
33 
34 #include "misc.h"
35 #include "log.h"
36 #include "xmalloc.h"
37 
38 /* remove newline at end of string */
39 char *
40 chop(char *s)
41 {
42 	char *t = s;
43 	while (*t) {
44 		if (*t == '\n' || *t == '\r') {
45 			*t = '\0';
46 			return s;
47 		}
48 		t++;
49 	}
50 	return s;
51 
52 }
53 
54 /* set/unset filedescriptor to non-blocking */
55 void
56 set_nonblock(int fd)
57 {
58 	int val;
59 
60 	val = fcntl(fd, F_GETFL, 0);
61 	if (val < 0) {
62 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
63 		return;
64 	}
65 	if (val & O_NONBLOCK) {
66 		debug2("fd %d is O_NONBLOCK", fd);
67 		return;
68 	}
69 	debug("fd %d setting O_NONBLOCK", fd);
70 	val |= O_NONBLOCK;
71 	if (fcntl(fd, F_SETFL, val) == -1)
72 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s",
73 		    fd, strerror(errno));
74 }
75 
76 void
77 unset_nonblock(int fd)
78 {
79 	int val;
80 
81 	val = fcntl(fd, F_GETFL, 0);
82 	if (val < 0) {
83 		error("fcntl(%d, F_GETFL, 0): %s", fd, strerror(errno));
84 		return;
85 	}
86 	if (!(val & O_NONBLOCK)) {
87 		debug2("fd %d is not O_NONBLOCK", fd);
88 		return;
89 	}
90 	debug("fd %d clearing O_NONBLOCK", fd);
91 	val &= ~O_NONBLOCK;
92 	if (fcntl(fd, F_SETFL, val) == -1)
93 		debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s",
94 		    fd, strerror(errno));
95 }
96 
97 /* disable nagle on socket */
98 void
99 set_nodelay(int fd)
100 {
101 	int opt;
102 	socklen_t optlen;
103 
104 	optlen = sizeof opt;
105 	if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
106 		error("getsockopt TCP_NODELAY: %.100s", strerror(errno));
107 		return;
108 	}
109 	if (opt == 1) {
110 		debug2("fd %d is TCP_NODELAY", fd);
111 		return;
112 	}
113 	opt = 1;
114 	debug("fd %d setting TCP_NODELAY", fd);
115 	if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
116 		error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
117 }
118 
119 /* Characters considered whitespace in strsep calls. */
120 #define WHITESPACE " \t\r\n"
121 
122 /*
123  * Function returns a pointer to the 1st token on the line. Such a token can
124  * be an empty string in the case of '*s' equal to " value". It changes the
125  * first whitespace token or '=' character after the 1st token to '\0'. Upon
126  * return it changes '*s' to point to the first character of the next token.
127  * That token may be an empty string if the 1st token was followed only by
128  * whitespace or it could be a NULL pointer if the line contained one token
129  * only.
130  */
131 char *
132 strdelim(char **s)
133 {
134 	char *old;
135 	int wspace = 0;
136 
137 	if (*s == NULL)
138 		return NULL;
139 
140 	old = *s;
141 
142 	*s = strpbrk(*s, WHITESPACE "=");
143 	if (*s == NULL)
144 		return (old);
145 
146 	/* Allow only one '=' to be skipped */
147 	if (*s[0] == '=')
148 		wspace = 1;
149 	*s[0] = '\0';
150 
151 	*s += strspn(*s + 1, WHITESPACE) + 1;
152 	if (*s[0] == '=' && !wspace)
153 		*s += strspn(*s + 1, WHITESPACE) + 1;
154 
155 	return (old);
156 }
157 
158 struct passwd *
159 pwcopy(struct passwd *pw)
160 {
161 	struct passwd *copy = xmalloc(sizeof(*copy));
162 
163 	memset(copy, 0, sizeof(*copy));
164 	copy->pw_name = xstrdup(pw->pw_name);
165 	copy->pw_passwd = xstrdup(pw->pw_passwd);
166 	copy->pw_gecos = xstrdup(pw->pw_gecos);
167 	copy->pw_uid = pw->pw_uid;
168 	copy->pw_gid = pw->pw_gid;
169 #ifdef HAVE_PW_EXPIRE_IN_PASSWD
170 	copy->pw_expire = pw->pw_expire;
171 #endif
172 #ifdef HAVE_PW_CHANGE_IN_PASSWD
173 	copy->pw_change = pw->pw_change;
174 #endif
175 #ifdef HAVE_PW_CLASS_IN_PASSWD
176 	copy->pw_class = xstrdup(pw->pw_class);
177 #endif
178 	copy->pw_dir = xstrdup(pw->pw_dir);
179 	copy->pw_shell = xstrdup(pw->pw_shell);
180 	return copy;
181 }
182 
183 void
184 pwfree(struct passwd **pw)
185 {
186 	struct passwd *p;
187 
188 	if (pw == NULL || *pw == NULL)
189 		return;
190 
191 	p = *pw;
192 	*pw = NULL;
193 
194 	xfree(p->pw_name);
195 	xfree(p->pw_passwd);
196 	xfree(p->pw_gecos);
197 #ifdef HAVE_PW_CLASS_IN_PASSWD
198 	xfree(p->pw_class);
199 #endif
200 	xfree(p->pw_dir);
201 	xfree(p->pw_shell);
202 	xfree(p);
203 }
204 
205 /*
206  * Convert ASCII string to TCP/IP port number.
207  * Port must be >0 and <=65535.
208  * Return 0 if invalid.
209  */
210 int
211 a2port(const char *s)
212 {
213 	long port;
214 	char *endp;
215 
216 	errno = 0;
217 	port = strtol(s, &endp, 0);
218 	if (s == endp || *endp != '\0' ||
219 	    (errno == ERANGE && (port == LONG_MIN || port == LONG_MAX)) ||
220 	    port <= 0 || port > 65535)
221 		return 0;
222 
223 	return port;
224 }
225 
226 #define SECONDS		1
227 #define MINUTES		(SECONDS * 60)
228 #define HOURS		(MINUTES * 60)
229 #define DAYS		(HOURS * 24)
230 #define WEEKS		(DAYS * 7)
231 
232 /*
233  * Convert a time string into seconds; format is
234  * a sequence of:
235  *      time[qualifier]
236  *
237  * Valid time qualifiers are:
238  *      <none>  seconds
239  *      s|S     seconds
240  *      m|M     minutes
241  *      h|H     hours
242  *      d|D     days
243  *      w|W     weeks
244  *
245  * Examples:
246  *      90m     90 minutes
247  *      1h30m   90 minutes
248  *      2d      2 days
249  *      1w      1 week
250  *
251  * Return -1 if time string is invalid.
252  */
253 long
254 convtime(const char *s)
255 {
256 	long total, secs;
257 	const char *p;
258 	char *endp;
259 
260 	errno = 0;
261 	total = 0;
262 	p = s;
263 
264 	if (p == NULL || *p == '\0')
265 		return -1;
266 
267 	while (*p) {
268 		secs = strtol(p, &endp, 10);
269 		if (p == endp ||
270 		    (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
271 		    secs < 0)
272 			return -1;
273 
274 		switch (*endp++) {
275 		case '\0':
276 			endp--;
277 			break;
278 		case 's':
279 		case 'S':
280 			break;
281 		case 'm':
282 		case 'M':
283 			secs *= MINUTES;
284 			break;
285 		case 'h':
286 		case 'H':
287 			secs *= HOURS;
288 			break;
289 		case 'd':
290 		case 'D':
291 			secs *= DAYS;
292 			break;
293 		case 'w':
294 		case 'W':
295 			secs *= WEEKS;
296 			break;
297 		default:
298 			return -1;
299 		}
300 		total += secs;
301 		if (total < 0)
302 			return -1;
303 		p = endp;
304 	}
305 
306 	return total;
307 }
308 
309 /*
310  * Search for next delimiter between hostnames/addresses and ports.
311  * Argument may be modified (for termination).
312  * Returns *cp if parsing succeeds.
313  * *cp is set to the start of the next delimiter, if one was found.
314  * If this is the last field, *cp is set to NULL.
315  */
316 char *
317 hpdelim(char **cp)
318 {
319 	char *s, *old;
320 
321 	if (cp == NULL || *cp == NULL)
322 		return NULL;
323 
324 	old = s = *cp;
325 	if (*s == '[') {
326 		if ((s = strchr(s, ']')) == NULL)
327 			return NULL;
328 		else
329 			s++;
330 	} else if ((s = strpbrk(s, ":/")) == NULL)
331 		s = *cp + strlen(*cp); /* skip to end (see first case below) */
332 
333 	switch (*s) {
334 	case '\0':
335 		*cp = NULL;	/* no more fields*/
336 		break;
337 
338 	case ':':
339 	case '/':
340 		*s = '\0';	/* terminate */
341 		*cp = s + 1;
342 		break;
343 
344 	default:
345 		return NULL;
346 	}
347 
348 	return old;
349 }
350 
351 char *
352 cleanhostname(char *host)
353 {
354 	if (*host == '[' && host[strlen(host) - 1] == ']') {
355 		host[strlen(host) - 1] = '\0';
356 		return (host + 1);
357 	} else
358 		return host;
359 }
360 
361 char *
362 colon(char *cp)
363 {
364 	int flag = 0;
365 
366 	if (*cp == ':')		/* Leading colon is part of file name. */
367 		return (0);
368 	if (*cp == '[')
369 		flag = 1;
370 
371 	for (; *cp; ++cp) {
372 		if (*cp == '@' && *(cp+1) == '[')
373 			flag = 1;
374 		if (*cp == ']' && *(cp+1) == ':' && flag)
375 			return (cp+1);
376 		if (*cp == ':' && !flag)
377 			return (cp);
378 		if (*cp == '/')
379 			return (0);
380 	}
381 	return (0);
382 }
383 
384 /* function to assist building execv() arguments */
385 /* PRINTFLIKE2 */
386 void
387 addargs(arglist *args, char *fmt, ...)
388 {
389 	va_list ap;
390 	char buf[1024];
391 
392 	va_start(ap, fmt);
393 	vsnprintf(buf, sizeof(buf), fmt, ap);
394 	va_end(ap);
395 
396 	if (args->list == NULL) {
397 		args->nalloc = 32;
398 		args->num = 0;
399 	} else if (args->num+2 >= args->nalloc)
400 		args->nalloc *= 2;
401 
402 	args->list = xrealloc(args->list, args->nalloc * sizeof(char *));
403 	args->list[args->num++] = xstrdup(buf);
404 	args->list[args->num] = NULL;
405 }
406 
407 void
408 replacearg(arglist *args, u_int which, char *fmt, ...)
409 {
410 	va_list ap;
411 	char *cp;
412 	int r;
413 
414 	va_start(ap, fmt);
415 	r = vasprintf(&cp, fmt, ap);
416 	va_end(ap);
417 	if (r == -1)
418 		fatal("replacearg: argument too long");
419 
420 	if (which >= args->num)
421 		fatal("replacearg: tried to replace invalid arg %d >= %d",
422 		    which, args->num);
423 	xfree(args->list[which]);
424 	args->list[which] = cp;
425 }
426 
427 void
428 freeargs(arglist *args)
429 {
430 	u_int i;
431 
432 	if (args->list != NULL) {
433 		for (i = 0; i < args->num; i++)
434 			xfree(args->list[i]);
435 		xfree(args->list);
436 		args->nalloc = args->num = 0;
437 		args->list = NULL;
438 	}
439 }
440 
441 /*
442  * Ensure that file descriptors 0, 1 and 2 are open or directed to /dev/null,
443  * do not touch those that are already open.
444  */
445 void
446 sanitise_stdfd(void)
447 {
448 	int nullfd, dupfd;
449 
450 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
451 		fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
452 		exit(1);
453 	}
454 	while (++dupfd <= 2) {
455 		/* Only clobber closed fds */
456 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
457 			continue;
458 		if (dup2(nullfd, dupfd) == -1) {
459 			fprintf(stderr, "dup2: %s", strerror(errno));
460 			exit(1);
461 		}
462 	}
463 	if (nullfd > 2)
464 		close(nullfd);
465 }
466 
467 char *
468 tohex(const void *vp, size_t l)
469 {
470 	const u_char *p = (const u_char *)vp;
471 	char b[3], *r;
472 	size_t i, hl;
473 
474 	if (l > 65536)
475 		return xstrdup("tohex: length > 65536");
476 
477 	hl = l * 2 + 1;
478 	r = xcalloc(1, hl);
479 	for (i = 0; i < l; i++) {
480 		snprintf(b, sizeof(b), "%02x", p[i]);
481 		strlcat(r, b, hl);
482 	}
483 	return (r);
484 }
485 
486 u_int64_t
487 get_u64(const void *vp)
488 {
489 	const u_char *p = (const u_char *)vp;
490 	u_int64_t v;
491 
492 	v  = (u_int64_t)p[0] << 56;
493 	v |= (u_int64_t)p[1] << 48;
494 	v |= (u_int64_t)p[2] << 40;
495 	v |= (u_int64_t)p[3] << 32;
496 	v |= (u_int64_t)p[4] << 24;
497 	v |= (u_int64_t)p[5] << 16;
498 	v |= (u_int64_t)p[6] << 8;
499 	v |= (u_int64_t)p[7];
500 
501 	return (v);
502 }
503 
504 u_int32_t
505 get_u32(const void *vp)
506 {
507 	const u_char *p = (const u_char *)vp;
508 	u_int32_t v;
509 
510 	v  = (u_int32_t)p[0] << 24;
511 	v |= (u_int32_t)p[1] << 16;
512 	v |= (u_int32_t)p[2] << 8;
513 	v |= (u_int32_t)p[3];
514 
515 	return (v);
516 }
517 
518 u_int16_t
519 get_u16(const void *vp)
520 {
521 	const u_char *p = (const u_char *)vp;
522 	u_int16_t v;
523 
524 	v  = (u_int16_t)p[0] << 8;
525 	v |= (u_int16_t)p[1];
526 
527 	return (v);
528 }
529 
530 void
531 put_u64(void *vp, u_int64_t v)
532 {
533 	u_char *p = (u_char *)vp;
534 
535 	p[0] = (u_char)(v >> 56) & 0xff;
536 	p[1] = (u_char)(v >> 48) & 0xff;
537 	p[2] = (u_char)(v >> 40) & 0xff;
538 	p[3] = (u_char)(v >> 32) & 0xff;
539 	p[4] = (u_char)(v >> 24) & 0xff;
540 	p[5] = (u_char)(v >> 16) & 0xff;
541 	p[6] = (u_char)(v >> 8) & 0xff;
542 	p[7] = (u_char)v & 0xff;
543 }
544 
545 void
546 put_u32(void *vp, u_int32_t v)
547 {
548 	u_char *p = (u_char *)vp;
549 
550 	p[0] = (u_char)(v >> 24) & 0xff;
551 	p[1] = (u_char)(v >> 16) & 0xff;
552 	p[2] = (u_char)(v >> 8) & 0xff;
553 	p[3] = (u_char)v & 0xff;
554 }
555 
556 
557 void
558 put_u16(void *vp, u_int16_t v)
559 {
560 	u_char *p = (u_char *)vp;
561 
562 	p[0] = (u_char)(v >> 8) & 0xff;
563 	p[1] = (u_char)v & 0xff;
564 }
565 
566 mysig_t
567 mysignal(int sig, mysig_t act)
568 {
569 #ifdef HAVE_SIGACTION
570 	struct sigaction sa, osa;
571 
572 	if (sigaction(sig, NULL, &osa) == -1)
573 		return (mysig_t) -1;
574 	if (osa.sa_handler != act) {
575 		memset(&sa, 0, sizeof(sa));
576 		sigemptyset(&sa.sa_mask);
577 		sa.sa_flags = 0;
578 #if defined(SA_INTERRUPT)
579 		if (sig == SIGALRM)
580 			sa.sa_flags |= SA_INTERRUPT;
581 #endif
582 		sa.sa_handler = act;
583 		if (sigaction(sig, &sa, NULL) == -1)
584 			return (mysig_t) -1;
585 	}
586 	return (osa.sa_handler);
587 #else
588 	return (signal(sig, act));
589 #endif
590 }
591 
592 /*
593  * Return true if argument is one of "yes", "true", "no" or "false". If
594  * 'active' is 0 than we are in a non-matching Host section of the
595  * configuration file so we check the syntax but will not set the value of
596  * '*option'. Otherwise we set its value if not already set.
597  */
598 int
599 get_yes_no_flag(int *option, const char *arg, const char *filename, int linenum,
600     int active)
601 {
602 	int value = -1;
603 
604 	if (arg == NULL || *arg == '\0')
605 		fatal("%.200s line %d: Missing argument.", filename, linenum);
606 	if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
607 		value = 1;
608 	else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
609 		value = 0;
610 
611 	if (active && *option == -1 && value != -1)
612 		*option = value;
613 
614 	return (value != -1);
615 }
616 
617 /*
618  * Convert a string to lowercase. The string returned is an internally allocated
619  * one so the consumer of this function is not expected to change it or free it.
620  */
621 char *
622 tolowercase(const char *s)
623 {
624 	int i, len;
625 	static int lenret = 0;
626 	static char *ret = NULL;
627 
628 	/* allocate a new string if the old one it not long enough to store s */
629 	len = strlen(s) + 1;
630 	if (len > lenret) {
631 		if (ret != NULL)
632 			xfree(ret);
633 		ret = xmalloc(len);
634 		lenret = len;
635 	}
636 
637 	/* process the string including the ending '\0' */
638 	for (i = 0; i < len; ++i)
639 		ret[i] = tolower(s[i]);
640 
641 	return (ret);
642 }
643