xref: /titanic_44/usr/src/cmd/ssh/libssh/common/misc.c (revision b9238976491622ad75a67ab0c12edf99e36212b9)
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 char *
310 cleanhostname(char *host)
311 {
312 	if (*host == '[' && host[strlen(host) - 1] == ']') {
313 		host[strlen(host) - 1] = '\0';
314 		return (host + 1);
315 	} else
316 		return host;
317 }
318 
319 char *
320 colon(char *cp)
321 {
322 	int flag = 0;
323 
324 	if (*cp == ':')		/* Leading colon is part of file name. */
325 		return (0);
326 	if (*cp == '[')
327 		flag = 1;
328 
329 	for (; *cp; ++cp) {
330 		if (*cp == '@' && *(cp+1) == '[')
331 			flag = 1;
332 		if (*cp == ']' && *(cp+1) == ':' && flag)
333 			return (cp+1);
334 		if (*cp == ':' && !flag)
335 			return (cp);
336 		if (*cp == '/')
337 			return (0);
338 	}
339 	return (0);
340 }
341 
342 /* function to assist building execv() arguments */
343 /* PRINTFLIKE2 */
344 void
345 addargs(arglist *args, char *fmt, ...)
346 {
347 	va_list ap;
348 	char buf[1024];
349 
350 	va_start(ap, fmt);
351 	vsnprintf(buf, sizeof(buf), fmt, ap);
352 	va_end(ap);
353 
354 	if (args->list == NULL) {
355 		args->nalloc = 32;
356 		args->num = 0;
357 	} else if (args->num+2 >= args->nalloc)
358 		args->nalloc *= 2;
359 
360 	args->list = xrealloc(args->list, args->nalloc * sizeof(char *));
361 	args->list[args->num++] = xstrdup(buf);
362 	args->list[args->num] = NULL;
363 }
364 
365 void
366 replacearg(arglist *args, u_int which, char *fmt, ...)
367 {
368 	va_list ap;
369 	char *cp;
370 	int r;
371 
372 	va_start(ap, fmt);
373 	r = vasprintf(&cp, fmt, ap);
374 	va_end(ap);
375 	if (r == -1)
376 		fatal("replacearg: argument too long");
377 
378 	if (which >= args->num)
379 		fatal("replacearg: tried to replace invalid arg %d >= %d",
380 		    which, args->num);
381 	xfree(args->list[which]);
382 	args->list[which] = cp;
383 }
384 
385 void
386 freeargs(arglist *args)
387 {
388 	u_int i;
389 
390 	if (args->list != NULL) {
391 		for (i = 0; i < args->num; i++)
392 			xfree(args->list[i]);
393 		xfree(args->list);
394 		args->nalloc = args->num = 0;
395 		args->list = NULL;
396 	}
397 }
398 
399 /*
400  * Ensure that file descriptors 0, 1 and 2 are open or directed to /dev/null,
401  * do not touch those that are already open.
402  */
403 void
404 sanitise_stdfd(void)
405 {
406 	int nullfd, dupfd;
407 
408 	if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
409 		fprintf(stderr, "Couldn't open /dev/null: %s", strerror(errno));
410 		exit(1);
411 	}
412 	while (++dupfd <= 2) {
413 		/* Only clobber closed fds */
414 		if (fcntl(dupfd, F_GETFL, 0) >= 0)
415 			continue;
416 		if (dup2(nullfd, dupfd) == -1) {
417 			fprintf(stderr, "dup2: %s", strerror(errno));
418 			exit(1);
419 		}
420 	}
421 	if (nullfd > 2)
422 		close(nullfd);
423 }
424 
425 char *
426 tohex(const void *vp, size_t l)
427 {
428 	const u_char *p = (const u_char *)vp;
429 	char b[3], *r;
430 	size_t i, hl;
431 
432 	if (l > 65536)
433 		return xstrdup("tohex: length > 65536");
434 
435 	hl = l * 2 + 1;
436 	r = xcalloc(1, hl);
437 	for (i = 0; i < l; i++) {
438 		snprintf(b, sizeof(b), "%02x", p[i]);
439 		strlcat(r, b, hl);
440 	}
441 	return (r);
442 }
443 
444 u_int64_t
445 get_u64(const void *vp)
446 {
447 	const u_char *p = (const u_char *)vp;
448 	u_int64_t v;
449 
450 	v  = (u_int64_t)p[0] << 56;
451 	v |= (u_int64_t)p[1] << 48;
452 	v |= (u_int64_t)p[2] << 40;
453 	v |= (u_int64_t)p[3] << 32;
454 	v |= (u_int64_t)p[4] << 24;
455 	v |= (u_int64_t)p[5] << 16;
456 	v |= (u_int64_t)p[6] << 8;
457 	v |= (u_int64_t)p[7];
458 
459 	return (v);
460 }
461 
462 u_int32_t
463 get_u32(const void *vp)
464 {
465 	const u_char *p = (const u_char *)vp;
466 	u_int32_t v;
467 
468 	v  = (u_int32_t)p[0] << 24;
469 	v |= (u_int32_t)p[1] << 16;
470 	v |= (u_int32_t)p[2] << 8;
471 	v |= (u_int32_t)p[3];
472 
473 	return (v);
474 }
475 
476 u_int16_t
477 get_u16(const void *vp)
478 {
479 	const u_char *p = (const u_char *)vp;
480 	u_int16_t v;
481 
482 	v  = (u_int16_t)p[0] << 8;
483 	v |= (u_int16_t)p[1];
484 
485 	return (v);
486 }
487 
488 void
489 put_u64(void *vp, u_int64_t v)
490 {
491 	u_char *p = (u_char *)vp;
492 
493 	p[0] = (u_char)(v >> 56) & 0xff;
494 	p[1] = (u_char)(v >> 48) & 0xff;
495 	p[2] = (u_char)(v >> 40) & 0xff;
496 	p[3] = (u_char)(v >> 32) & 0xff;
497 	p[4] = (u_char)(v >> 24) & 0xff;
498 	p[5] = (u_char)(v >> 16) & 0xff;
499 	p[6] = (u_char)(v >> 8) & 0xff;
500 	p[7] = (u_char)v & 0xff;
501 }
502 
503 void
504 put_u32(void *vp, u_int32_t v)
505 {
506 	u_char *p = (u_char *)vp;
507 
508 	p[0] = (u_char)(v >> 24) & 0xff;
509 	p[1] = (u_char)(v >> 16) & 0xff;
510 	p[2] = (u_char)(v >> 8) & 0xff;
511 	p[3] = (u_char)v & 0xff;
512 }
513 
514 
515 void
516 put_u16(void *vp, u_int16_t v)
517 {
518 	u_char *p = (u_char *)vp;
519 
520 	p[0] = (u_char)(v >> 8) & 0xff;
521 	p[1] = (u_char)v & 0xff;
522 }
523 
524 mysig_t
525 mysignal(int sig, mysig_t act)
526 {
527 #ifdef HAVE_SIGACTION
528 	struct sigaction sa, osa;
529 
530 	if (sigaction(sig, NULL, &osa) == -1)
531 		return (mysig_t) -1;
532 	if (osa.sa_handler != act) {
533 		memset(&sa, 0, sizeof(sa));
534 		sigemptyset(&sa.sa_mask);
535 		sa.sa_flags = 0;
536 #if defined(SA_INTERRUPT)
537 		if (sig == SIGALRM)
538 			sa.sa_flags |= SA_INTERRUPT;
539 #endif
540 		sa.sa_handler = act;
541 		if (sigaction(sig, &sa, NULL) == -1)
542 			return (mysig_t) -1;
543 	}
544 	return (osa.sa_handler);
545 #else
546 	return (signal(sig, act));
547 #endif
548 }
549 
550 /*
551  * Return true if argument is one of "yes", "true", "no" or "false". If
552  * 'active' is 0 than we are in a non-matching Host section of the
553  * configuration file so we check the syntax but will not set the value of
554  * '*option'. Otherwise we set its value if not already set.
555  */
556 int
557 get_yes_no_flag(int *option, const char *arg, const char *filename, int linenum,
558     int active)
559 {
560 	int value = -1;
561 
562 	if (arg == NULL || *arg == '\0')
563 		fatal("%.200s line %d: Missing argument.", filename, linenum);
564 	if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
565 		value = 1;
566 	else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
567 		value = 0;
568 
569 	if (active && *option == -1 && value != -1)
570 		*option = value;
571 
572 	return (value != -1);
573 }
574 
575 /*
576  * Convert a string to lowercase. The string returned is an internally allocated
577  * one so the consumer of this function is not expected to change it or free it.
578  */
579 char *
580 tolowercase(const char *s)
581 {
582 	int i, len;
583 	static int lenret = 0;
584 	static char *ret = NULL;
585 
586 	/* allocate a new string if the old one it not long enough to store s */
587 	len = strlen(s) + 1;
588 	if (len > lenret) {
589 		if (ret != NULL)
590 			xfree(ret);
591 		ret = xmalloc(len);
592 		lenret = len;
593 	}
594 
595 	/* process the string including the ending '\0' */
596 	for (i = 0; i < len; ++i)
597 		ret[i] = tolower(s[i]);
598 
599 	return (ret);
600 }
601