1 /* $OpenBSD: misc.c,v 1.147 2020/04/25 06:59:36 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/stat.h>
33 #include <sys/time.h>
34 #include <sys/wait.h>
35 #include <sys/un.h>
36
37 #include <limits.h>
38 #ifdef HAVE_LIBGEN_H
39 # include <libgen.h>
40 #endif
41 #ifdef HAVE_POLL_H
42 #include <poll.h>
43 #endif
44 #include <signal.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <time.h>
50 #include <unistd.h>
51
52 #include <netinet/in.h>
53 #include <netinet/in_systm.h>
54 #include <netinet/ip.h>
55 #include <netinet/tcp.h>
56 #include <arpa/inet.h>
57
58 #include <ctype.h>
59 #include <errno.h>
60 #include <fcntl.h>
61 #include <netdb.h>
62 #ifdef HAVE_PATHS_H
63 # include <paths.h>
64 #include <pwd.h>
65 #endif
66 #ifdef SSH_TUN_OPENBSD
67 #include <net/if.h>
68 #endif
69
70 #include "xmalloc.h"
71 #include "misc.h"
72 #include "log.h"
73 #include "ssh.h"
74 #include "sshbuf.h"
75 #include "ssherr.h"
76 #include "platform.h"
77
78 /* remove newline at end of string */
79 char *
chop(char * s)80 chop(char *s)
81 {
82 char *t = s;
83 while (*t) {
84 if (*t == '\n' || *t == '\r') {
85 *t = '\0';
86 return s;
87 }
88 t++;
89 }
90 return s;
91
92 }
93
94 /* set/unset filedescriptor to non-blocking */
95 int
set_nonblock(int fd)96 set_nonblock(int fd)
97 {
98 int val;
99
100 val = fcntl(fd, F_GETFL);
101 if (val == -1) {
102 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
103 return (-1);
104 }
105 if (val & O_NONBLOCK) {
106 debug3("fd %d is O_NONBLOCK", fd);
107 return (0);
108 }
109 debug2("fd %d setting O_NONBLOCK", fd);
110 val |= O_NONBLOCK;
111 if (fcntl(fd, F_SETFL, val) == -1) {
112 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
113 strerror(errno));
114 return (-1);
115 }
116 return (0);
117 }
118
119 int
unset_nonblock(int fd)120 unset_nonblock(int fd)
121 {
122 int val;
123
124 val = fcntl(fd, F_GETFL);
125 if (val == -1) {
126 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
127 return (-1);
128 }
129 if (!(val & O_NONBLOCK)) {
130 debug3("fd %d is not O_NONBLOCK", fd);
131 return (0);
132 }
133 debug("fd %d clearing O_NONBLOCK", fd);
134 val &= ~O_NONBLOCK;
135 if (fcntl(fd, F_SETFL, val) == -1) {
136 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
137 fd, strerror(errno));
138 return (-1);
139 }
140 return (0);
141 }
142
143 const char *
ssh_gai_strerror(int gaierr)144 ssh_gai_strerror(int gaierr)
145 {
146 if (gaierr == EAI_SYSTEM && errno != 0)
147 return strerror(errno);
148 return gai_strerror(gaierr);
149 }
150
151 /* disable nagle on socket */
152 void
set_nodelay(int fd)153 set_nodelay(int fd)
154 {
155 int opt;
156 socklen_t optlen;
157
158 optlen = sizeof opt;
159 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
160 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
161 return;
162 }
163 if (opt == 1) {
164 debug2("fd %d is TCP_NODELAY", fd);
165 return;
166 }
167 opt = 1;
168 debug2("fd %d setting TCP_NODELAY", fd);
169 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
170 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
171 }
172
173 /* Allow local port reuse in TIME_WAIT */
174 int
set_reuseaddr(int fd)175 set_reuseaddr(int fd)
176 {
177 int on = 1;
178
179 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
180 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
181 return -1;
182 }
183 return 0;
184 }
185
186 /* Get/set routing domain */
187 char *
get_rdomain(int fd)188 get_rdomain(int fd)
189 {
190 #if defined(HAVE_SYS_GET_RDOMAIN)
191 return sys_get_rdomain(fd);
192 #elif defined(__OpenBSD__)
193 int rtable;
194 char *ret;
195 socklen_t len = sizeof(rtable);
196
197 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) {
198 error("Failed to get routing domain for fd %d: %s",
199 fd, strerror(errno));
200 return NULL;
201 }
202 xasprintf(&ret, "%d", rtable);
203 return ret;
204 #else /* defined(__OpenBSD__) */
205 return NULL;
206 #endif
207 }
208
209 int
set_rdomain(int fd,const char * name)210 set_rdomain(int fd, const char *name)
211 {
212 #if defined(HAVE_SYS_SET_RDOMAIN)
213 return sys_set_rdomain(fd, name);
214 #elif defined(__OpenBSD__)
215 int rtable;
216 const char *errstr;
217
218 if (name == NULL)
219 return 0; /* default table */
220
221 rtable = (int)strtonum(name, 0, 255, &errstr);
222 if (errstr != NULL) {
223 /* Shouldn't happen */
224 error("Invalid routing domain \"%s\": %s", name, errstr);
225 return -1;
226 }
227 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE,
228 &rtable, sizeof(rtable)) == -1) {
229 error("Failed to set routing domain %d on fd %d: %s",
230 rtable, fd, strerror(errno));
231 return -1;
232 }
233 return 0;
234 #else /* defined(__OpenBSD__) */
235 error("Setting routing domain is not supported on this platform");
236 return -1;
237 #endif
238 }
239
240 /*
241 * Wait up to *timeoutp milliseconds for events on fd. Updates
242 * *timeoutp with time remaining.
243 * Returns 0 if fd ready or -1 on timeout or error (see errno).
244 */
245 static int
waitfd(int fd,int * timeoutp,short events)246 waitfd(int fd, int *timeoutp, short events)
247 {
248 struct pollfd pfd;
249 struct timeval t_start;
250 int oerrno, r;
251
252 monotime_tv(&t_start);
253 pfd.fd = fd;
254 pfd.events = events;
255 for (; *timeoutp >= 0;) {
256 r = poll(&pfd, 1, *timeoutp);
257 oerrno = errno;
258 ms_subtract_diff(&t_start, timeoutp);
259 errno = oerrno;
260 if (r > 0)
261 return 0;
262 else if (r == -1 && errno != EAGAIN)
263 return -1;
264 else if (r == 0)
265 break;
266 }
267 /* timeout */
268 errno = ETIMEDOUT;
269 return -1;
270 }
271
272 /*
273 * Wait up to *timeoutp milliseconds for fd to be readable. Updates
274 * *timeoutp with time remaining.
275 * Returns 0 if fd ready or -1 on timeout or error (see errno).
276 */
277 int
waitrfd(int fd,int * timeoutp)278 waitrfd(int fd, int *timeoutp) {
279 return waitfd(fd, timeoutp, POLLIN);
280 }
281
282 /*
283 * Attempt a non-blocking connect(2) to the specified address, waiting up to
284 * *timeoutp milliseconds for the connection to complete. If the timeout is
285 * <=0, then wait indefinitely.
286 *
287 * Returns 0 on success or -1 on failure.
288 */
289 int
timeout_connect(int sockfd,const struct sockaddr * serv_addr,socklen_t addrlen,int * timeoutp)290 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
291 socklen_t addrlen, int *timeoutp)
292 {
293 int optval = 0;
294 socklen_t optlen = sizeof(optval);
295
296 /* No timeout: just do a blocking connect() */
297 if (timeoutp == NULL || *timeoutp <= 0)
298 return connect(sockfd, serv_addr, addrlen);
299
300 set_nonblock(sockfd);
301 if (connect(sockfd, serv_addr, addrlen) == 0) {
302 /* Succeeded already? */
303 unset_nonblock(sockfd);
304 return 0;
305 } else if (errno != EINPROGRESS)
306 return -1;
307
308 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1)
309 return -1;
310
311 /* Completed or failed */
312 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) {
313 debug("getsockopt: %s", strerror(errno));
314 return -1;
315 }
316 if (optval != 0) {
317 errno = optval;
318 return -1;
319 }
320 unset_nonblock(sockfd);
321 return 0;
322 }
323
324 /* Characters considered whitespace in strsep calls. */
325 #define WHITESPACE " \t\r\n"
326 #define QUOTE "\""
327
328 /* return next token in configuration line */
329 static char *
strdelim_internal(char ** s,int split_equals)330 strdelim_internal(char **s, int split_equals)
331 {
332 char *old;
333 int wspace = 0;
334
335 if (*s == NULL)
336 return NULL;
337
338 old = *s;
339
340 *s = strpbrk(*s,
341 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE);
342 if (*s == NULL)
343 return (old);
344
345 if (*s[0] == '\"') {
346 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
347 /* Find matching quote */
348 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
349 return (NULL); /* no matching quote */
350 } else {
351 *s[0] = '\0';
352 *s += strspn(*s + 1, WHITESPACE) + 1;
353 return (old);
354 }
355 }
356
357 /* Allow only one '=' to be skipped */
358 if (split_equals && *s[0] == '=')
359 wspace = 1;
360 *s[0] = '\0';
361
362 /* Skip any extra whitespace after first token */
363 *s += strspn(*s + 1, WHITESPACE) + 1;
364 if (split_equals && *s[0] == '=' && !wspace)
365 *s += strspn(*s + 1, WHITESPACE) + 1;
366
367 return (old);
368 }
369
370 /*
371 * Return next token in configuration line; splts on whitespace or a
372 * single '=' character.
373 */
374 char *
strdelim(char ** s)375 strdelim(char **s)
376 {
377 return strdelim_internal(s, 1);
378 }
379
380 /*
381 * Return next token in configuration line; splts on whitespace only.
382 */
383 char *
strdelimw(char ** s)384 strdelimw(char **s)
385 {
386 return strdelim_internal(s, 0);
387 }
388
389 struct passwd *
pwcopy(struct passwd * pw)390 pwcopy(struct passwd *pw)
391 {
392 struct passwd *copy = xcalloc(1, sizeof(*copy));
393
394 copy->pw_name = xstrdup(pw->pw_name);
395 copy->pw_passwd = pw->pw_passwd ? xstrdup(pw->pw_passwd) : NULL;
396 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
397 copy->pw_gecos = xstrdup(pw->pw_gecos);
398 #endif
399 copy->pw_uid = pw->pw_uid;
400 copy->pw_gid = pw->pw_gid;
401 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
402 copy->pw_expire = pw->pw_expire;
403 #endif
404 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
405 copy->pw_change = pw->pw_change;
406 #endif
407 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
408 copy->pw_class = xstrdup(pw->pw_class);
409 #endif
410 copy->pw_dir = xstrdup(pw->pw_dir);
411 copy->pw_shell = xstrdup(pw->pw_shell);
412 return copy;
413 }
414
415 /*
416 * Convert ASCII string to TCP/IP port number.
417 * Port must be >=0 and <=65535.
418 * Return -1 if invalid.
419 */
420 int
a2port(const char * s)421 a2port(const char *s)
422 {
423 struct servent *se;
424 long long port;
425 const char *errstr;
426
427 port = strtonum(s, 0, 65535, &errstr);
428 if (errstr == NULL)
429 return (int)port;
430 if ((se = getservbyname(s, "tcp")) != NULL)
431 return ntohs(se->s_port);
432 return -1;
433 }
434
435 int
a2tun(const char * s,int * remote)436 a2tun(const char *s, int *remote)
437 {
438 const char *errstr = NULL;
439 char *sp, *ep;
440 int tun;
441
442 if (remote != NULL) {
443 *remote = SSH_TUNID_ANY;
444 sp = xstrdup(s);
445 if ((ep = strchr(sp, ':')) == NULL) {
446 free(sp);
447 return (a2tun(s, NULL));
448 }
449 ep[0] = '\0'; ep++;
450 *remote = a2tun(ep, NULL);
451 tun = a2tun(sp, NULL);
452 free(sp);
453 return (*remote == SSH_TUNID_ERR ? *remote : tun);
454 }
455
456 if (strcasecmp(s, "any") == 0)
457 return (SSH_TUNID_ANY);
458
459 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
460 if (errstr != NULL)
461 return (SSH_TUNID_ERR);
462
463 return (tun);
464 }
465
466 #define SECONDS 1
467 #define MINUTES (SECONDS * 60)
468 #define HOURS (MINUTES * 60)
469 #define DAYS (HOURS * 24)
470 #define WEEKS (DAYS * 7)
471
472 /*
473 * Convert a time string into seconds; format is
474 * a sequence of:
475 * time[qualifier]
476 *
477 * Valid time qualifiers are:
478 * <none> seconds
479 * s|S seconds
480 * m|M minutes
481 * h|H hours
482 * d|D days
483 * w|W weeks
484 *
485 * Examples:
486 * 90m 90 minutes
487 * 1h30m 90 minutes
488 * 2d 2 days
489 * 1w 1 week
490 *
491 * Return -1 if time string is invalid.
492 */
493 long
convtime(const char * s)494 convtime(const char *s)
495 {
496 long total, secs, multiplier = 1;
497 const char *p;
498 char *endp;
499
500 errno = 0;
501 total = 0;
502 p = s;
503
504 if (p == NULL || *p == '\0')
505 return -1;
506
507 while (*p) {
508 secs = strtol(p, &endp, 10);
509 if (p == endp ||
510 (errno == ERANGE && (secs == LONG_MIN || secs == LONG_MAX)) ||
511 secs < 0)
512 return -1;
513
514 switch (*endp++) {
515 case '\0':
516 endp--;
517 break;
518 case 's':
519 case 'S':
520 break;
521 case 'm':
522 case 'M':
523 multiplier = MINUTES;
524 break;
525 case 'h':
526 case 'H':
527 multiplier = HOURS;
528 break;
529 case 'd':
530 case 'D':
531 multiplier = DAYS;
532 break;
533 case 'w':
534 case 'W':
535 multiplier = WEEKS;
536 break;
537 default:
538 return -1;
539 }
540 if (secs >= LONG_MAX / multiplier)
541 return -1;
542 secs *= multiplier;
543 if (total >= LONG_MAX - secs)
544 return -1;
545 total += secs;
546 if (total < 0)
547 return -1;
548 p = endp;
549 }
550
551 return total;
552 }
553
554 /*
555 * Returns a standardized host+port identifier string.
556 * Caller must free returned string.
557 */
558 char *
put_host_port(const char * host,u_short port)559 put_host_port(const char *host, u_short port)
560 {
561 char *hoststr;
562
563 if (port == 0 || port == SSH_DEFAULT_PORT)
564 return(xstrdup(host));
565 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1)
566 fatal("put_host_port: asprintf: %s", strerror(errno));
567 debug3("put_host_port: %s", hoststr);
568 return hoststr;
569 }
570
571 /*
572 * Search for next delimiter between hostnames/addresses and ports.
573 * Argument may be modified (for termination).
574 * Returns *cp if parsing succeeds.
575 * *cp is set to the start of the next field, if one was found.
576 * The delimiter char, if present, is stored in delim.
577 * If this is the last field, *cp is set to NULL.
578 */
579 char *
hpdelim2(char ** cp,char * delim)580 hpdelim2(char **cp, char *delim)
581 {
582 char *s, *old;
583
584 if (cp == NULL || *cp == NULL)
585 return NULL;
586
587 old = s = *cp;
588 if (*s == '[') {
589 if ((s = strchr(s, ']')) == NULL)
590 return NULL;
591 else
592 s++;
593 } else if ((s = strpbrk(s, ":/")) == NULL)
594 s = *cp + strlen(*cp); /* skip to end (see first case below) */
595
596 switch (*s) {
597 case '\0':
598 *cp = NULL; /* no more fields*/
599 break;
600
601 case ':':
602 case '/':
603 if (delim != NULL)
604 *delim = *s;
605 *s = '\0'; /* terminate */
606 *cp = s + 1;
607 break;
608
609 default:
610 return NULL;
611 }
612
613 return old;
614 }
615
616 char *
hpdelim(char ** cp)617 hpdelim(char **cp)
618 {
619 return hpdelim2(cp, NULL);
620 }
621
622 char *
cleanhostname(char * host)623 cleanhostname(char *host)
624 {
625 if (*host == '[' && host[strlen(host) - 1] == ']') {
626 host[strlen(host) - 1] = '\0';
627 return (host + 1);
628 } else
629 return host;
630 }
631
632 char *
colon(char * cp)633 colon(char *cp)
634 {
635 int flag = 0;
636
637 if (*cp == ':') /* Leading colon is part of file name. */
638 return NULL;
639 if (*cp == '[')
640 flag = 1;
641
642 for (; *cp; ++cp) {
643 if (*cp == '@' && *(cp+1) == '[')
644 flag = 1;
645 if (*cp == ']' && *(cp+1) == ':' && flag)
646 return (cp+1);
647 if (*cp == ':' && !flag)
648 return (cp);
649 if (*cp == '/')
650 return NULL;
651 }
652 return NULL;
653 }
654
655 /*
656 * Parse a [user@]host:[path] string.
657 * Caller must free returned user, host and path.
658 * Any of the pointer return arguments may be NULL (useful for syntax checking).
659 * If user was not specified then *userp will be set to NULL.
660 * If host was not specified then *hostp will be set to NULL.
661 * If path was not specified then *pathp will be set to ".".
662 * Returns 0 on success, -1 on failure.
663 */
664 int
parse_user_host_path(const char * s,char ** userp,char ** hostp,char ** pathp)665 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp)
666 {
667 char *user = NULL, *host = NULL, *path = NULL;
668 char *sdup, *tmp;
669 int ret = -1;
670
671 if (userp != NULL)
672 *userp = NULL;
673 if (hostp != NULL)
674 *hostp = NULL;
675 if (pathp != NULL)
676 *pathp = NULL;
677
678 sdup = xstrdup(s);
679
680 /* Check for remote syntax: [user@]host:[path] */
681 if ((tmp = colon(sdup)) == NULL)
682 goto out;
683
684 /* Extract optional path */
685 *tmp++ = '\0';
686 if (*tmp == '\0')
687 tmp = ".";
688 path = xstrdup(tmp);
689
690 /* Extract optional user and mandatory host */
691 tmp = strrchr(sdup, '@');
692 if (tmp != NULL) {
693 *tmp++ = '\0';
694 host = xstrdup(cleanhostname(tmp));
695 if (*sdup != '\0')
696 user = xstrdup(sdup);
697 } else {
698 host = xstrdup(cleanhostname(sdup));
699 user = NULL;
700 }
701
702 /* Success */
703 if (userp != NULL) {
704 *userp = user;
705 user = NULL;
706 }
707 if (hostp != NULL) {
708 *hostp = host;
709 host = NULL;
710 }
711 if (pathp != NULL) {
712 *pathp = path;
713 path = NULL;
714 }
715 ret = 0;
716 out:
717 free(sdup);
718 free(user);
719 free(host);
720 free(path);
721 return ret;
722 }
723
724 /*
725 * Parse a [user@]host[:port] string.
726 * Caller must free returned user and host.
727 * Any of the pointer return arguments may be NULL (useful for syntax checking).
728 * If user was not specified then *userp will be set to NULL.
729 * If port was not specified then *portp will be -1.
730 * Returns 0 on success, -1 on failure.
731 */
732 int
parse_user_host_port(const char * s,char ** userp,char ** hostp,int * portp)733 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
734 {
735 char *sdup, *cp, *tmp;
736 char *user = NULL, *host = NULL;
737 int port = -1, ret = -1;
738
739 if (userp != NULL)
740 *userp = NULL;
741 if (hostp != NULL)
742 *hostp = NULL;
743 if (portp != NULL)
744 *portp = -1;
745
746 if ((sdup = tmp = strdup(s)) == NULL)
747 return -1;
748 /* Extract optional username */
749 if ((cp = strrchr(tmp, '@')) != NULL) {
750 *cp = '\0';
751 if (*tmp == '\0')
752 goto out;
753 if ((user = strdup(tmp)) == NULL)
754 goto out;
755 tmp = cp + 1;
756 }
757 /* Extract mandatory hostname */
758 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0')
759 goto out;
760 host = xstrdup(cleanhostname(cp));
761 /* Convert and verify optional port */
762 if (tmp != NULL && *tmp != '\0') {
763 if ((port = a2port(tmp)) <= 0)
764 goto out;
765 }
766 /* Success */
767 if (userp != NULL) {
768 *userp = user;
769 user = NULL;
770 }
771 if (hostp != NULL) {
772 *hostp = host;
773 host = NULL;
774 }
775 if (portp != NULL)
776 *portp = port;
777 ret = 0;
778 out:
779 free(sdup);
780 free(user);
781 free(host);
782 return ret;
783 }
784
785 /*
786 * Converts a two-byte hex string to decimal.
787 * Returns the decimal value or -1 for invalid input.
788 */
789 static int
hexchar(const char * s)790 hexchar(const char *s)
791 {
792 unsigned char result[2];
793 int i;
794
795 for (i = 0; i < 2; i++) {
796 if (s[i] >= '0' && s[i] <= '9')
797 result[i] = (unsigned char)(s[i] - '0');
798 else if (s[i] >= 'a' && s[i] <= 'f')
799 result[i] = (unsigned char)(s[i] - 'a') + 10;
800 else if (s[i] >= 'A' && s[i] <= 'F')
801 result[i] = (unsigned char)(s[i] - 'A') + 10;
802 else
803 return -1;
804 }
805 return (result[0] << 4) | result[1];
806 }
807
808 /*
809 * Decode an url-encoded string.
810 * Returns a newly allocated string on success or NULL on failure.
811 */
812 static char *
urldecode(const char * src)813 urldecode(const char *src)
814 {
815 char *ret, *dst;
816 int ch;
817
818 ret = xmalloc(strlen(src) + 1);
819 for (dst = ret; *src != '\0'; src++) {
820 switch (*src) {
821 case '+':
822 *dst++ = ' ';
823 break;
824 case '%':
825 if (!isxdigit((unsigned char)src[1]) ||
826 !isxdigit((unsigned char)src[2]) ||
827 (ch = hexchar(src + 1)) == -1) {
828 free(ret);
829 return NULL;
830 }
831 *dst++ = ch;
832 src += 2;
833 break;
834 default:
835 *dst++ = *src;
836 break;
837 }
838 }
839 *dst = '\0';
840
841 return ret;
842 }
843
844 /*
845 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI.
846 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04
847 * Either user or path may be url-encoded (but not host or port).
848 * Caller must free returned user, host and path.
849 * Any of the pointer return arguments may be NULL (useful for syntax checking)
850 * but the scheme must always be specified.
851 * If user was not specified then *userp will be set to NULL.
852 * If port was not specified then *portp will be -1.
853 * If path was not specified then *pathp will be set to NULL.
854 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri.
855 */
856 int
parse_uri(const char * scheme,const char * uri,char ** userp,char ** hostp,int * portp,char ** pathp)857 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp,
858 int *portp, char **pathp)
859 {
860 char *uridup, *cp, *tmp, ch;
861 char *user = NULL, *host = NULL, *path = NULL;
862 int port = -1, ret = -1;
863 size_t len;
864
865 len = strlen(scheme);
866 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0)
867 return 1;
868 uri += len + 3;
869
870 if (userp != NULL)
871 *userp = NULL;
872 if (hostp != NULL)
873 *hostp = NULL;
874 if (portp != NULL)
875 *portp = -1;
876 if (pathp != NULL)
877 *pathp = NULL;
878
879 uridup = tmp = xstrdup(uri);
880
881 /* Extract optional ssh-info (username + connection params) */
882 if ((cp = strchr(tmp, '@')) != NULL) {
883 char *delim;
884
885 *cp = '\0';
886 /* Extract username and connection params */
887 if ((delim = strchr(tmp, ';')) != NULL) {
888 /* Just ignore connection params for now */
889 *delim = '\0';
890 }
891 if (*tmp == '\0') {
892 /* Empty username */
893 goto out;
894 }
895 if ((user = urldecode(tmp)) == NULL)
896 goto out;
897 tmp = cp + 1;
898 }
899
900 /* Extract mandatory hostname */
901 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0')
902 goto out;
903 host = xstrdup(cleanhostname(cp));
904 if (!valid_domain(host, 0, NULL))
905 goto out;
906
907 if (tmp != NULL && *tmp != '\0') {
908 if (ch == ':') {
909 /* Convert and verify port. */
910 if ((cp = strchr(tmp, '/')) != NULL)
911 *cp = '\0';
912 if ((port = a2port(tmp)) <= 0)
913 goto out;
914 tmp = cp ? cp + 1 : NULL;
915 }
916 if (tmp != NULL && *tmp != '\0') {
917 /* Extract optional path */
918 if ((path = urldecode(tmp)) == NULL)
919 goto out;
920 }
921 }
922
923 /* Success */
924 if (userp != NULL) {
925 *userp = user;
926 user = NULL;
927 }
928 if (hostp != NULL) {
929 *hostp = host;
930 host = NULL;
931 }
932 if (portp != NULL)
933 *portp = port;
934 if (pathp != NULL) {
935 *pathp = path;
936 path = NULL;
937 }
938 ret = 0;
939 out:
940 free(uridup);
941 free(user);
942 free(host);
943 free(path);
944 return ret;
945 }
946
947 /* function to assist building execv() arguments */
948 void
addargs(arglist * args,char * fmt,...)949 addargs(arglist *args, char *fmt, ...)
950 {
951 va_list ap;
952 char *cp;
953 u_int nalloc;
954 int r;
955
956 va_start(ap, fmt);
957 r = vasprintf(&cp, fmt, ap);
958 va_end(ap);
959 if (r == -1)
960 fatal("addargs: argument too long");
961
962 nalloc = args->nalloc;
963 if (args->list == NULL) {
964 nalloc = 32;
965 args->num = 0;
966 } else if (args->num+2 >= nalloc)
967 nalloc *= 2;
968
969 args->list = xrecallocarray(args->list, args->nalloc, nalloc, sizeof(char *));
970 args->nalloc = nalloc;
971 args->list[args->num++] = cp;
972 args->list[args->num] = NULL;
973 }
974
975 void
replacearg(arglist * args,u_int which,char * fmt,...)976 replacearg(arglist *args, u_int which, char *fmt, ...)
977 {
978 va_list ap;
979 char *cp;
980 int r;
981
982 va_start(ap, fmt);
983 r = vasprintf(&cp, fmt, ap);
984 va_end(ap);
985 if (r == -1)
986 fatal("replacearg: argument too long");
987
988 if (which >= args->num)
989 fatal("replacearg: tried to replace invalid arg %d >= %d",
990 which, args->num);
991 free(args->list[which]);
992 args->list[which] = cp;
993 }
994
995 void
freeargs(arglist * args)996 freeargs(arglist *args)
997 {
998 u_int i;
999
1000 if (args->list != NULL) {
1001 for (i = 0; i < args->num; i++)
1002 free(args->list[i]);
1003 free(args->list);
1004 args->nalloc = args->num = 0;
1005 args->list = NULL;
1006 }
1007 }
1008
1009 /*
1010 * Expands tildes in the file name. Returns data allocated by xmalloc.
1011 * Warning: this calls getpw*.
1012 */
1013 char *
tilde_expand_filename(const char * filename,uid_t uid)1014 tilde_expand_filename(const char *filename, uid_t uid)
1015 {
1016 const char *path, *sep;
1017 char user[128], *ret;
1018 struct passwd *pw;
1019 u_int len, slash;
1020
1021 if (*filename != '~')
1022 return (xstrdup(filename));
1023 filename++;
1024
1025 path = strchr(filename, '/');
1026 if (path != NULL && path > filename) { /* ~user/path */
1027 slash = path - filename;
1028 if (slash > sizeof(user) - 1)
1029 fatal("tilde_expand_filename: ~username too long");
1030 memcpy(user, filename, slash);
1031 user[slash] = '\0';
1032 if ((pw = getpwnam(user)) == NULL)
1033 fatal("tilde_expand_filename: No such user %s", user);
1034 } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */
1035 fatal("tilde_expand_filename: No such uid %ld", (long)uid);
1036
1037 /* Make sure directory has a trailing '/' */
1038 len = strlen(pw->pw_dir);
1039 if (len == 0 || pw->pw_dir[len - 1] != '/')
1040 sep = "/";
1041 else
1042 sep = "";
1043
1044 /* Skip leading '/' from specified path */
1045 if (path != NULL)
1046 filename = path + 1;
1047
1048 if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX)
1049 fatal("tilde_expand_filename: Path too long");
1050
1051 return (ret);
1052 }
1053
1054 /*
1055 * Expand a string with a set of %[char] escapes. A number of escapes may be
1056 * specified as (char *escape_chars, char *replacement) pairs. The list must
1057 * be terminated by a NULL escape_char. Returns replaced string in memory
1058 * allocated by xmalloc.
1059 */
1060 char *
percent_expand(const char * string,...)1061 percent_expand(const char *string, ...)
1062 {
1063 #define EXPAND_MAX_KEYS 16
1064 u_int num_keys, i;
1065 struct {
1066 const char *key;
1067 const char *repl;
1068 } keys[EXPAND_MAX_KEYS];
1069 struct sshbuf *buf;
1070 va_list ap;
1071 int r;
1072 char *ret;
1073
1074 if ((buf = sshbuf_new()) == NULL)
1075 fatal("%s: sshbuf_new failed", __func__);
1076
1077 /* Gather keys */
1078 va_start(ap, string);
1079 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
1080 keys[num_keys].key = va_arg(ap, char *);
1081 if (keys[num_keys].key == NULL)
1082 break;
1083 keys[num_keys].repl = va_arg(ap, char *);
1084 if (keys[num_keys].repl == NULL)
1085 fatal("%s: NULL replacement", __func__);
1086 }
1087 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
1088 fatal("%s: too many keys", __func__);
1089 va_end(ap);
1090
1091 /* Expand string */
1092 for (i = 0; *string != '\0'; string++) {
1093 if (*string != '%') {
1094 append:
1095 if ((r = sshbuf_put_u8(buf, *string)) != 0) {
1096 fatal("%s: sshbuf_put_u8: %s",
1097 __func__, ssh_err(r));
1098 }
1099 continue;
1100 }
1101 string++;
1102 /* %% case */
1103 if (*string == '%')
1104 goto append;
1105 if (*string == '\0')
1106 fatal("%s: invalid format", __func__);
1107 for (i = 0; i < num_keys; i++) {
1108 if (strchr(keys[i].key, *string) != NULL) {
1109 if ((r = sshbuf_put(buf, keys[i].repl,
1110 strlen(keys[i].repl))) != 0) {
1111 fatal("%s: sshbuf_put: %s",
1112 __func__, ssh_err(r));
1113 }
1114 break;
1115 }
1116 }
1117 if (i >= num_keys)
1118 fatal("%s: unknown key %%%c", __func__, *string);
1119 }
1120 if ((ret = sshbuf_dup_string(buf)) == NULL)
1121 fatal("%s: sshbuf_dup_string failed", __func__);
1122 sshbuf_free(buf);
1123 return ret;
1124 #undef EXPAND_MAX_KEYS
1125 }
1126
1127 int
tun_open(int tun,int mode,char ** ifname)1128 tun_open(int tun, int mode, char **ifname)
1129 {
1130 #if defined(CUSTOM_SYS_TUN_OPEN)
1131 return (sys_tun_open(tun, mode, ifname));
1132 #elif defined(SSH_TUN_OPENBSD)
1133 struct ifreq ifr;
1134 char name[100];
1135 int fd = -1, sock;
1136 const char *tunbase = "tun";
1137
1138 if (ifname != NULL)
1139 *ifname = NULL;
1140
1141 if (mode == SSH_TUNMODE_ETHERNET)
1142 tunbase = "tap";
1143
1144 /* Open the tunnel device */
1145 if (tun <= SSH_TUNID_MAX) {
1146 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
1147 fd = open(name, O_RDWR);
1148 } else if (tun == SSH_TUNID_ANY) {
1149 for (tun = 100; tun >= 0; tun--) {
1150 snprintf(name, sizeof(name), "/dev/%s%d",
1151 tunbase, tun);
1152 if ((fd = open(name, O_RDWR)) >= 0)
1153 break;
1154 }
1155 } else {
1156 debug("%s: invalid tunnel %u", __func__, tun);
1157 return -1;
1158 }
1159
1160 if (fd == -1) {
1161 debug("%s: %s open: %s", __func__, name, strerror(errno));
1162 return -1;
1163 }
1164
1165 debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
1166
1167 /* Bring interface up if it is not already */
1168 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
1169 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1170 goto failed;
1171
1172 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
1173 debug("%s: get interface %s flags: %s", __func__,
1174 ifr.ifr_name, strerror(errno));
1175 goto failed;
1176 }
1177
1178 if (!(ifr.ifr_flags & IFF_UP)) {
1179 ifr.ifr_flags |= IFF_UP;
1180 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
1181 debug("%s: activate interface %s: %s", __func__,
1182 ifr.ifr_name, strerror(errno));
1183 goto failed;
1184 }
1185 }
1186
1187 if (ifname != NULL)
1188 *ifname = xstrdup(ifr.ifr_name);
1189
1190 close(sock);
1191 return fd;
1192
1193 failed:
1194 if (fd >= 0)
1195 close(fd);
1196 if (sock >= 0)
1197 close(sock);
1198 return -1;
1199 #else
1200 error("Tunnel interfaces are not supported on this platform");
1201 return (-1);
1202 #endif
1203 }
1204
1205 void
sanitise_stdfd(void)1206 sanitise_stdfd(void)
1207 {
1208 int nullfd, dupfd;
1209
1210 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1211 fprintf(stderr, "Couldn't open /dev/null: %s\n",
1212 strerror(errno));
1213 exit(1);
1214 }
1215 while (++dupfd <= STDERR_FILENO) {
1216 /* Only populate closed fds. */
1217 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
1218 if (dup2(nullfd, dupfd) == -1) {
1219 fprintf(stderr, "dup2: %s\n", strerror(errno));
1220 exit(1);
1221 }
1222 }
1223 }
1224 if (nullfd > STDERR_FILENO)
1225 close(nullfd);
1226 }
1227
1228 char *
tohex(const void * vp,size_t l)1229 tohex(const void *vp, size_t l)
1230 {
1231 const u_char *p = (const u_char *)vp;
1232 char b[3], *r;
1233 size_t i, hl;
1234
1235 if (l > 65536)
1236 return xstrdup("tohex: length > 65536");
1237
1238 hl = l * 2 + 1;
1239 r = xcalloc(1, hl);
1240 for (i = 0; i < l; i++) {
1241 snprintf(b, sizeof(b), "%02x", p[i]);
1242 strlcat(r, b, hl);
1243 }
1244 return (r);
1245 }
1246
1247 /*
1248 * Extend string *sp by the specified format. If *sp is not NULL (or empty),
1249 * then the separator 'sep' will be prepended before the formatted arguments.
1250 * Extended strings are heap allocated.
1251 */
1252 void
xextendf(char ** sp,const char * sep,const char * fmt,...)1253 xextendf(char **sp, const char *sep, const char *fmt, ...)
1254 {
1255 va_list ap;
1256 char *tmp1, *tmp2;
1257
1258 va_start(ap, fmt);
1259 xvasprintf(&tmp1, fmt, ap);
1260 va_end(ap);
1261
1262 if (*sp == NULL || **sp == '\0') {
1263 free(*sp);
1264 *sp = tmp1;
1265 return;
1266 }
1267 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1);
1268 free(tmp1);
1269 free(*sp);
1270 *sp = tmp2;
1271 }
1272
1273
1274 u_int64_t
get_u64(const void * vp)1275 get_u64(const void *vp)
1276 {
1277 const u_char *p = (const u_char *)vp;
1278 u_int64_t v;
1279
1280 v = (u_int64_t)p[0] << 56;
1281 v |= (u_int64_t)p[1] << 48;
1282 v |= (u_int64_t)p[2] << 40;
1283 v |= (u_int64_t)p[3] << 32;
1284 v |= (u_int64_t)p[4] << 24;
1285 v |= (u_int64_t)p[5] << 16;
1286 v |= (u_int64_t)p[6] << 8;
1287 v |= (u_int64_t)p[7];
1288
1289 return (v);
1290 }
1291
1292 u_int32_t
get_u32(const void * vp)1293 get_u32(const void *vp)
1294 {
1295 const u_char *p = (const u_char *)vp;
1296 u_int32_t v;
1297
1298 v = (u_int32_t)p[0] << 24;
1299 v |= (u_int32_t)p[1] << 16;
1300 v |= (u_int32_t)p[2] << 8;
1301 v |= (u_int32_t)p[3];
1302
1303 return (v);
1304 }
1305
1306 u_int32_t
get_u32_le(const void * vp)1307 get_u32_le(const void *vp)
1308 {
1309 const u_char *p = (const u_char *)vp;
1310 u_int32_t v;
1311
1312 v = (u_int32_t)p[0];
1313 v |= (u_int32_t)p[1] << 8;
1314 v |= (u_int32_t)p[2] << 16;
1315 v |= (u_int32_t)p[3] << 24;
1316
1317 return (v);
1318 }
1319
1320 u_int16_t
get_u16(const void * vp)1321 get_u16(const void *vp)
1322 {
1323 const u_char *p = (const u_char *)vp;
1324 u_int16_t v;
1325
1326 v = (u_int16_t)p[0] << 8;
1327 v |= (u_int16_t)p[1];
1328
1329 return (v);
1330 }
1331
1332 void
put_u64(void * vp,u_int64_t v)1333 put_u64(void *vp, u_int64_t v)
1334 {
1335 u_char *p = (u_char *)vp;
1336
1337 p[0] = (u_char)(v >> 56) & 0xff;
1338 p[1] = (u_char)(v >> 48) & 0xff;
1339 p[2] = (u_char)(v >> 40) & 0xff;
1340 p[3] = (u_char)(v >> 32) & 0xff;
1341 p[4] = (u_char)(v >> 24) & 0xff;
1342 p[5] = (u_char)(v >> 16) & 0xff;
1343 p[6] = (u_char)(v >> 8) & 0xff;
1344 p[7] = (u_char)v & 0xff;
1345 }
1346
1347 void
put_u32(void * vp,u_int32_t v)1348 put_u32(void *vp, u_int32_t v)
1349 {
1350 u_char *p = (u_char *)vp;
1351
1352 p[0] = (u_char)(v >> 24) & 0xff;
1353 p[1] = (u_char)(v >> 16) & 0xff;
1354 p[2] = (u_char)(v >> 8) & 0xff;
1355 p[3] = (u_char)v & 0xff;
1356 }
1357
1358 void
put_u32_le(void * vp,u_int32_t v)1359 put_u32_le(void *vp, u_int32_t v)
1360 {
1361 u_char *p = (u_char *)vp;
1362
1363 p[0] = (u_char)v & 0xff;
1364 p[1] = (u_char)(v >> 8) & 0xff;
1365 p[2] = (u_char)(v >> 16) & 0xff;
1366 p[3] = (u_char)(v >> 24) & 0xff;
1367 }
1368
1369 void
put_u16(void * vp,u_int16_t v)1370 put_u16(void *vp, u_int16_t v)
1371 {
1372 u_char *p = (u_char *)vp;
1373
1374 p[0] = (u_char)(v >> 8) & 0xff;
1375 p[1] = (u_char)v & 0xff;
1376 }
1377
1378 void
ms_subtract_diff(struct timeval * start,int * ms)1379 ms_subtract_diff(struct timeval *start, int *ms)
1380 {
1381 struct timeval diff, finish;
1382
1383 monotime_tv(&finish);
1384 timersub(&finish, start, &diff);
1385 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
1386 }
1387
1388 void
ms_to_timeval(struct timeval * tv,int ms)1389 ms_to_timeval(struct timeval *tv, int ms)
1390 {
1391 if (ms < 0)
1392 ms = 0;
1393 tv->tv_sec = ms / 1000;
1394 tv->tv_usec = (ms % 1000) * 1000;
1395 }
1396
1397 void
monotime_ts(struct timespec * ts)1398 monotime_ts(struct timespec *ts)
1399 {
1400 struct timeval tv;
1401 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \
1402 defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME))
1403 static int gettime_failed = 0;
1404
1405 if (!gettime_failed) {
1406 # ifdef CLOCK_BOOTTIME
1407 if (clock_gettime(CLOCK_BOOTTIME, ts) == 0)
1408 return;
1409 # endif /* CLOCK_BOOTTIME */
1410 # ifdef CLOCK_MONOTONIC
1411 if (clock_gettime(CLOCK_MONOTONIC, ts) == 0)
1412 return;
1413 # endif /* CLOCK_MONOTONIC */
1414 # ifdef CLOCK_REALTIME
1415 /* Not monotonic, but we're almost out of options here. */
1416 if (clock_gettime(CLOCK_REALTIME, ts) == 0)
1417 return;
1418 # endif /* CLOCK_REALTIME */
1419 debug3("clock_gettime: %s", strerror(errno));
1420 gettime_failed = 1;
1421 }
1422 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */
1423 gettimeofday(&tv, NULL);
1424 ts->tv_sec = tv.tv_sec;
1425 ts->tv_nsec = (long)tv.tv_usec * 1000;
1426 }
1427
1428 void
monotime_tv(struct timeval * tv)1429 monotime_tv(struct timeval *tv)
1430 {
1431 struct timespec ts;
1432
1433 monotime_ts(&ts);
1434 tv->tv_sec = ts.tv_sec;
1435 tv->tv_usec = ts.tv_nsec / 1000;
1436 }
1437
1438 time_t
monotime(void)1439 monotime(void)
1440 {
1441 struct timespec ts;
1442
1443 monotime_ts(&ts);
1444 return ts.tv_sec;
1445 }
1446
1447 double
monotime_double(void)1448 monotime_double(void)
1449 {
1450 struct timespec ts;
1451
1452 monotime_ts(&ts);
1453 return ts.tv_sec + ((double)ts.tv_nsec / 1000000000);
1454 }
1455
1456 void
bandwidth_limit_init(struct bwlimit * bw,u_int64_t kbps,size_t buflen)1457 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
1458 {
1459 bw->buflen = buflen;
1460 bw->rate = kbps;
1461 bw->thresh = buflen;
1462 bw->lamt = 0;
1463 timerclear(&bw->bwstart);
1464 timerclear(&bw->bwend);
1465 }
1466
1467 /* Callback from read/write loop to insert bandwidth-limiting delays */
1468 void
bandwidth_limit(struct bwlimit * bw,size_t read_len)1469 bandwidth_limit(struct bwlimit *bw, size_t read_len)
1470 {
1471 u_int64_t waitlen;
1472 struct timespec ts, rm;
1473
1474 bw->lamt += read_len;
1475 if (!timerisset(&bw->bwstart)) {
1476 monotime_tv(&bw->bwstart);
1477 return;
1478 }
1479 if (bw->lamt < bw->thresh)
1480 return;
1481
1482 monotime_tv(&bw->bwend);
1483 timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
1484 if (!timerisset(&bw->bwend))
1485 return;
1486
1487 bw->lamt *= 8;
1488 waitlen = (double)1000000L * bw->lamt / bw->rate;
1489
1490 bw->bwstart.tv_sec = waitlen / 1000000L;
1491 bw->bwstart.tv_usec = waitlen % 1000000L;
1492
1493 if (timercmp(&bw->bwstart, &bw->bwend, >)) {
1494 timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
1495
1496 /* Adjust the wait time */
1497 if (bw->bwend.tv_sec) {
1498 bw->thresh /= 2;
1499 if (bw->thresh < bw->buflen / 4)
1500 bw->thresh = bw->buflen / 4;
1501 } else if (bw->bwend.tv_usec < 10000) {
1502 bw->thresh *= 2;
1503 if (bw->thresh > bw->buflen * 8)
1504 bw->thresh = bw->buflen * 8;
1505 }
1506
1507 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
1508 while (nanosleep(&ts, &rm) == -1) {
1509 if (errno != EINTR)
1510 break;
1511 ts = rm;
1512 }
1513 }
1514
1515 bw->lamt = 0;
1516 monotime_tv(&bw->bwstart);
1517 }
1518
1519 /* Make a template filename for mk[sd]temp() */
1520 void
mktemp_proto(char * s,size_t len)1521 mktemp_proto(char *s, size_t len)
1522 {
1523 const char *tmpdir;
1524 int r;
1525
1526 if ((tmpdir = getenv("TMPDIR")) != NULL) {
1527 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
1528 if (r > 0 && (size_t)r < len)
1529 return;
1530 }
1531 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
1532 if (r < 0 || (size_t)r >= len)
1533 fatal("%s: template string too short", __func__);
1534 }
1535
1536 static const struct {
1537 const char *name;
1538 int value;
1539 } ipqos[] = {
1540 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */
1541 { "af11", IPTOS_DSCP_AF11 },
1542 { "af12", IPTOS_DSCP_AF12 },
1543 { "af13", IPTOS_DSCP_AF13 },
1544 { "af21", IPTOS_DSCP_AF21 },
1545 { "af22", IPTOS_DSCP_AF22 },
1546 { "af23", IPTOS_DSCP_AF23 },
1547 { "af31", IPTOS_DSCP_AF31 },
1548 { "af32", IPTOS_DSCP_AF32 },
1549 { "af33", IPTOS_DSCP_AF33 },
1550 { "af41", IPTOS_DSCP_AF41 },
1551 { "af42", IPTOS_DSCP_AF42 },
1552 { "af43", IPTOS_DSCP_AF43 },
1553 { "cs0", IPTOS_DSCP_CS0 },
1554 { "cs1", IPTOS_DSCP_CS1 },
1555 { "cs2", IPTOS_DSCP_CS2 },
1556 { "cs3", IPTOS_DSCP_CS3 },
1557 { "cs4", IPTOS_DSCP_CS4 },
1558 { "cs5", IPTOS_DSCP_CS5 },
1559 { "cs6", IPTOS_DSCP_CS6 },
1560 { "cs7", IPTOS_DSCP_CS7 },
1561 { "ef", IPTOS_DSCP_EF },
1562 { "le", IPTOS_DSCP_LE },
1563 { "lowdelay", IPTOS_LOWDELAY },
1564 { "throughput", IPTOS_THROUGHPUT },
1565 { "reliability", IPTOS_RELIABILITY },
1566 { NULL, -1 }
1567 };
1568
1569 int
parse_ipqos(const char * cp)1570 parse_ipqos(const char *cp)
1571 {
1572 u_int i;
1573 char *ep;
1574 long val;
1575
1576 if (cp == NULL)
1577 return -1;
1578 for (i = 0; ipqos[i].name != NULL; i++) {
1579 if (strcasecmp(cp, ipqos[i].name) == 0)
1580 return ipqos[i].value;
1581 }
1582 /* Try parsing as an integer */
1583 val = strtol(cp, &ep, 0);
1584 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1585 return -1;
1586 return val;
1587 }
1588
1589 const char *
iptos2str(int iptos)1590 iptos2str(int iptos)
1591 {
1592 int i;
1593 static char iptos_str[sizeof "0xff"];
1594
1595 for (i = 0; ipqos[i].name != NULL; i++) {
1596 if (ipqos[i].value == iptos)
1597 return ipqos[i].name;
1598 }
1599 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1600 return iptos_str;
1601 }
1602
1603 void
lowercase(char * s)1604 lowercase(char *s)
1605 {
1606 for (; *s; s++)
1607 *s = tolower((u_char)*s);
1608 }
1609
1610 int
unix_listener(const char * path,int backlog,int unlink_first)1611 unix_listener(const char *path, int backlog, int unlink_first)
1612 {
1613 struct sockaddr_un sunaddr;
1614 int saved_errno, sock;
1615
1616 memset(&sunaddr, 0, sizeof(sunaddr));
1617 sunaddr.sun_family = AF_UNIX;
1618 if (strlcpy(sunaddr.sun_path, path,
1619 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1620 error("%s: path \"%s\" too long for Unix domain socket",
1621 __func__, path);
1622 errno = ENAMETOOLONG;
1623 return -1;
1624 }
1625
1626 sock = socket(PF_UNIX, SOCK_STREAM, 0);
1627 if (sock == -1) {
1628 saved_errno = errno;
1629 error("%s: socket: %.100s", __func__, strerror(errno));
1630 errno = saved_errno;
1631 return -1;
1632 }
1633 if (unlink_first == 1) {
1634 if (unlink(path) != 0 && errno != ENOENT)
1635 error("unlink(%s): %.100s", path, strerror(errno));
1636 }
1637 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
1638 saved_errno = errno;
1639 error("%s: cannot bind to path %s: %s",
1640 __func__, path, strerror(errno));
1641 close(sock);
1642 errno = saved_errno;
1643 return -1;
1644 }
1645 if (listen(sock, backlog) == -1) {
1646 saved_errno = errno;
1647 error("%s: cannot listen on path %s: %s",
1648 __func__, path, strerror(errno));
1649 close(sock);
1650 unlink(path);
1651 errno = saved_errno;
1652 return -1;
1653 }
1654 return sock;
1655 }
1656
1657 void
sock_set_v6only(int s)1658 sock_set_v6only(int s)
1659 {
1660 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
1661 int on = 1;
1662
1663 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1664 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1665 error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1666 #endif
1667 }
1668
1669 /*
1670 * Compares two strings that maybe be NULL. Returns non-zero if strings
1671 * are both NULL or are identical, returns zero otherwise.
1672 */
1673 static int
strcmp_maybe_null(const char * a,const char * b)1674 strcmp_maybe_null(const char *a, const char *b)
1675 {
1676 if ((a == NULL && b != NULL) || (a != NULL && b == NULL))
1677 return 0;
1678 if (a != NULL && strcmp(a, b) != 0)
1679 return 0;
1680 return 1;
1681 }
1682
1683 /*
1684 * Compare two forwards, returning non-zero if they are identical or
1685 * zero otherwise.
1686 */
1687 int
forward_equals(const struct Forward * a,const struct Forward * b)1688 forward_equals(const struct Forward *a, const struct Forward *b)
1689 {
1690 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0)
1691 return 0;
1692 if (a->listen_port != b->listen_port)
1693 return 0;
1694 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0)
1695 return 0;
1696 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0)
1697 return 0;
1698 if (a->connect_port != b->connect_port)
1699 return 0;
1700 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0)
1701 return 0;
1702 /* allocated_port and handle are not checked */
1703 return 1;
1704 }
1705
1706 /* returns 1 if process is already daemonized, 0 otherwise */
1707 int
daemonized(void)1708 daemonized(void)
1709 {
1710 int fd;
1711
1712 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
1713 close(fd);
1714 return 0; /* have controlling terminal */
1715 }
1716 if (getppid() != 1)
1717 return 0; /* parent is not init */
1718 if (getsid(0) != getpid())
1719 return 0; /* not session leader */
1720 debug3("already daemonized");
1721 return 1;
1722 }
1723
1724
1725 /*
1726 * Splits 's' into an argument vector. Handles quoted string and basic
1727 * escape characters (\\, \", \'). Caller must free the argument vector
1728 * and its members.
1729 */
1730 int
argv_split(const char * s,int * argcp,char *** argvp)1731 argv_split(const char *s, int *argcp, char ***argvp)
1732 {
1733 int r = SSH_ERR_INTERNAL_ERROR;
1734 int argc = 0, quote, i, j;
1735 char *arg, **argv = xcalloc(1, sizeof(*argv));
1736
1737 *argvp = NULL;
1738 *argcp = 0;
1739
1740 for (i = 0; s[i] != '\0'; i++) {
1741 /* Skip leading whitespace */
1742 if (s[i] == ' ' || s[i] == '\t')
1743 continue;
1744
1745 /* Start of a token */
1746 quote = 0;
1747 if (s[i] == '\\' &&
1748 (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\'))
1749 i++;
1750 else if (s[i] == '\'' || s[i] == '"')
1751 quote = s[i++];
1752
1753 argv = xreallocarray(argv, (argc + 2), sizeof(*argv));
1754 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1);
1755 argv[argc] = NULL;
1756
1757 /* Copy the token in, removing escapes */
1758 for (j = 0; s[i] != '\0'; i++) {
1759 if (s[i] == '\\') {
1760 if (s[i + 1] == '\'' ||
1761 s[i + 1] == '\"' ||
1762 s[i + 1] == '\\') {
1763 i++; /* Skip '\' */
1764 arg[j++] = s[i];
1765 } else {
1766 /* Unrecognised escape */
1767 arg[j++] = s[i];
1768 }
1769 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t'))
1770 break; /* done */
1771 else if (quote != 0 && s[i] == quote)
1772 break; /* done */
1773 else
1774 arg[j++] = s[i];
1775 }
1776 if (s[i] == '\0') {
1777 if (quote != 0) {
1778 /* Ran out of string looking for close quote */
1779 r = SSH_ERR_INVALID_FORMAT;
1780 goto out;
1781 }
1782 break;
1783 }
1784 }
1785 /* Success */
1786 *argcp = argc;
1787 *argvp = argv;
1788 argc = 0;
1789 argv = NULL;
1790 r = 0;
1791 out:
1792 if (argc != 0 && argv != NULL) {
1793 for (i = 0; i < argc; i++)
1794 free(argv[i]);
1795 free(argv);
1796 }
1797 return r;
1798 }
1799
1800 /*
1801 * Reassemble an argument vector into a string, quoting and escaping as
1802 * necessary. Caller must free returned string.
1803 */
1804 char *
argv_assemble(int argc,char ** argv)1805 argv_assemble(int argc, char **argv)
1806 {
1807 int i, j, ws, r;
1808 char c, *ret;
1809 struct sshbuf *buf, *arg;
1810
1811 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL)
1812 fatal("%s: sshbuf_new failed", __func__);
1813
1814 for (i = 0; i < argc; i++) {
1815 ws = 0;
1816 sshbuf_reset(arg);
1817 for (j = 0; argv[i][j] != '\0'; j++) {
1818 r = 0;
1819 c = argv[i][j];
1820 switch (c) {
1821 case ' ':
1822 case '\t':
1823 ws = 1;
1824 r = sshbuf_put_u8(arg, c);
1825 break;
1826 case '\\':
1827 case '\'':
1828 case '"':
1829 if ((r = sshbuf_put_u8(arg, '\\')) != 0)
1830 break;
1831 /* FALLTHROUGH */
1832 default:
1833 r = sshbuf_put_u8(arg, c);
1834 break;
1835 }
1836 if (r != 0)
1837 fatal("%s: sshbuf_put_u8: %s",
1838 __func__, ssh_err(r));
1839 }
1840 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) ||
1841 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) ||
1842 (r = sshbuf_putb(buf, arg)) != 0 ||
1843 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0))
1844 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1845 }
1846 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL)
1847 fatal("%s: malloc failed", __func__);
1848 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf));
1849 ret[sshbuf_len(buf)] = '\0';
1850 sshbuf_free(buf);
1851 sshbuf_free(arg);
1852 return ret;
1853 }
1854
1855 /* Returns 0 if pid exited cleanly, non-zero otherwise */
1856 int
exited_cleanly(pid_t pid,const char * tag,const char * cmd,int quiet)1857 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)
1858 {
1859 int status;
1860
1861 while (waitpid(pid, &status, 0) == -1) {
1862 if (errno != EINTR) {
1863 error("%s: waitpid: %s", tag, strerror(errno));
1864 return -1;
1865 }
1866 }
1867 if (WIFSIGNALED(status)) {
1868 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status));
1869 return -1;
1870 } else if (WEXITSTATUS(status) != 0) {
1871 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO,
1872 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status));
1873 return -1;
1874 }
1875 return 0;
1876 }
1877
1878 /*
1879 * Check a given path for security. This is defined as all components
1880 * of the path to the file must be owned by either the owner of
1881 * of the file or root and no directories must be group or world writable.
1882 *
1883 * XXX Should any specific check be done for sym links ?
1884 *
1885 * Takes a file name, its stat information (preferably from fstat() to
1886 * avoid races), the uid of the expected owner, their home directory and an
1887 * error buffer plus max size as arguments.
1888 *
1889 * Returns 0 on success and -1 on failure
1890 */
1891 int
safe_path(const char * name,struct stat * stp,const char * pw_dir,uid_t uid,char * err,size_t errlen)1892 safe_path(const char *name, struct stat *stp, const char *pw_dir,
1893 uid_t uid, char *err, size_t errlen)
1894 {
1895 char buf[PATH_MAX], homedir[PATH_MAX];
1896 char *cp;
1897 int comparehome = 0;
1898 #if !defined(ANDROID)
1899 struct stat st;
1900 #endif
1901
1902 if (realpath(name, buf) == NULL) {
1903 snprintf(err, errlen, "realpath %s failed: %s", name,
1904 strerror(errno));
1905 return -1;
1906 }
1907 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
1908 comparehome = 1;
1909
1910 if (!S_ISREG(stp->st_mode)) {
1911 snprintf(err, errlen, "%s is not a regular file", buf);
1912 return -1;
1913 }
1914 if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) ||
1915 (stp->st_mode & 022) != 0) {
1916 snprintf(err, errlen, "bad ownership or modes for file %s",
1917 buf);
1918 return -1;
1919 }
1920
1921 /* for each component of the canonical path, walking upwards */
1922 for (;;) {
1923 if ((cp = dirname(buf)) == NULL) {
1924 snprintf(err, errlen, "dirname() failed");
1925 return -1;
1926 }
1927 strlcpy(buf, cp, sizeof(buf));
1928
1929 #if !defined(ANDROID)
1930 /* /data is owned by system user, which causes this check to fail */
1931 if (stat(buf, &st) == -1 ||
1932 (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) ||
1933 (st.st_mode & 022) != 0) {
1934 snprintf(err, errlen,
1935 "bad ownership or modes for directory %s", buf);
1936 return -1;
1937 }
1938 #endif
1939
1940 /* If are past the homedir then we can stop */
1941 if (comparehome && strcmp(homedir, buf) == 0)
1942 break;
1943
1944 /*
1945 * dirname should always complete with a "/" path,
1946 * but we can be paranoid and check for "." too
1947 */
1948 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
1949 break;
1950 }
1951 return 0;
1952 }
1953
1954 /*
1955 * Version of safe_path() that accepts an open file descriptor to
1956 * avoid races.
1957 *
1958 * Returns 0 on success and -1 on failure
1959 */
1960 int
safe_path_fd(int fd,const char * file,struct passwd * pw,char * err,size_t errlen)1961 safe_path_fd(int fd, const char *file, struct passwd *pw,
1962 char *err, size_t errlen)
1963 {
1964 struct stat st;
1965
1966 /* check the open file to avoid races */
1967 if (fstat(fd, &st) == -1) {
1968 snprintf(err, errlen, "cannot stat file %s: %s",
1969 file, strerror(errno));
1970 return -1;
1971 }
1972 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
1973 }
1974
1975 /*
1976 * Sets the value of the given variable in the environment. If the variable
1977 * already exists, its value is overridden.
1978 */
1979 void
child_set_env(char *** envp,u_int * envsizep,const char * name,const char * value)1980 child_set_env(char ***envp, u_int *envsizep, const char *name,
1981 const char *value)
1982 {
1983 char **env;
1984 u_int envsize;
1985 u_int i, namelen;
1986
1987 if (strchr(name, '=') != NULL) {
1988 error("Invalid environment variable \"%.100s\"", name);
1989 return;
1990 }
1991
1992 /*
1993 * If we're passed an uninitialized list, allocate a single null
1994 * entry before continuing.
1995 */
1996 if (*envp == NULL && *envsizep == 0) {
1997 *envp = xmalloc(sizeof(char *));
1998 *envp[0] = NULL;
1999 *envsizep = 1;
2000 }
2001
2002 /*
2003 * Find the slot where the value should be stored. If the variable
2004 * already exists, we reuse the slot; otherwise we append a new slot
2005 * at the end of the array, expanding if necessary.
2006 */
2007 env = *envp;
2008 namelen = strlen(name);
2009 for (i = 0; env[i]; i++)
2010 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
2011 break;
2012 if (env[i]) {
2013 /* Reuse the slot. */
2014 free(env[i]);
2015 } else {
2016 /* New variable. Expand if necessary. */
2017 envsize = *envsizep;
2018 if (i >= envsize - 1) {
2019 if (envsize >= 1000)
2020 fatal("child_set_env: too many env vars");
2021 envsize += 50;
2022 env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
2023 *envsizep = envsize;
2024 }
2025 /* Need to set the NULL pointer at end of array beyond the new slot. */
2026 env[i + 1] = NULL;
2027 }
2028
2029 /* Allocate space and format the variable in the appropriate slot. */
2030 /* XXX xasprintf */
2031 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
2032 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
2033 }
2034
2035 /*
2036 * Check and optionally lowercase a domain name, also removes trailing '.'
2037 * Returns 1 on success and 0 on failure, storing an error message in errstr.
2038 */
2039 int
valid_domain(char * name,int makelower,const char ** errstr)2040 valid_domain(char *name, int makelower, const char **errstr)
2041 {
2042 size_t i, l = strlen(name);
2043 u_char c, last = '\0';
2044 static char errbuf[256];
2045
2046 if (l == 0) {
2047 strlcpy(errbuf, "empty domain name", sizeof(errbuf));
2048 goto bad;
2049 }
2050 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) {
2051 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" "
2052 "starts with invalid character", name);
2053 goto bad;
2054 }
2055 for (i = 0; i < l; i++) {
2056 c = tolower((u_char)name[i]);
2057 if (makelower)
2058 name[i] = (char)c;
2059 if (last == '.' && c == '.') {
2060 snprintf(errbuf, sizeof(errbuf), "domain name "
2061 "\"%.100s\" contains consecutive separators", name);
2062 goto bad;
2063 }
2064 if (c != '.' && c != '-' && !isalnum(c) &&
2065 c != '_') /* technically invalid, but common */ {
2066 snprintf(errbuf, sizeof(errbuf), "domain name "
2067 "\"%.100s\" contains invalid characters", name);
2068 goto bad;
2069 }
2070 last = c;
2071 }
2072 if (name[l - 1] == '.')
2073 name[l - 1] = '\0';
2074 if (errstr != NULL)
2075 *errstr = NULL;
2076 return 1;
2077 bad:
2078 if (errstr != NULL)
2079 *errstr = errbuf;
2080 return 0;
2081 }
2082
2083 /*
2084 * Verify that a environment variable name (not including initial '$') is
2085 * valid; consisting of one or more alphanumeric or underscore characters only.
2086 * Returns 1 on valid, 0 otherwise.
2087 */
2088 int
valid_env_name(const char * name)2089 valid_env_name(const char *name)
2090 {
2091 const char *cp;
2092
2093 if (name[0] == '\0')
2094 return 0;
2095 for (cp = name; *cp != '\0'; cp++) {
2096 if (!isalnum((u_char)*cp) && *cp != '_')
2097 return 0;
2098 }
2099 return 1;
2100 }
2101
2102 const char *
atoi_err(const char * nptr,int * val)2103 atoi_err(const char *nptr, int *val)
2104 {
2105 const char *errstr = NULL;
2106 long long num;
2107
2108 if (nptr == NULL || *nptr == '\0')
2109 return "missing";
2110 num = strtonum(nptr, 0, INT_MAX, &errstr);
2111 if (errstr == NULL)
2112 *val = (int)num;
2113 return errstr;
2114 }
2115
2116 int
parse_absolute_time(const char * s,uint64_t * tp)2117 parse_absolute_time(const char *s, uint64_t *tp)
2118 {
2119 struct tm tm;
2120 time_t tt;
2121 char buf[32], *fmt;
2122
2123 *tp = 0;
2124
2125 /*
2126 * POSIX strptime says "The application shall ensure that there
2127 * is white-space or other non-alphanumeric characters between
2128 * any two conversion specifications" so arrange things this way.
2129 */
2130 switch (strlen(s)) {
2131 case 8: /* YYYYMMDD */
2132 fmt = "%Y-%m-%d";
2133 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
2134 break;
2135 case 12: /* YYYYMMDDHHMM */
2136 fmt = "%Y-%m-%dT%H:%M";
2137 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s",
2138 s, s + 4, s + 6, s + 8, s + 10);
2139 break;
2140 case 14: /* YYYYMMDDHHMMSS */
2141 fmt = "%Y-%m-%dT%H:%M:%S";
2142 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
2143 s, s + 4, s + 6, s + 8, s + 10, s + 12);
2144 break;
2145 default:
2146 return SSH_ERR_INVALID_FORMAT;
2147 }
2148
2149 memset(&tm, 0, sizeof(tm));
2150 if (strptime(buf, fmt, &tm) == NULL)
2151 return SSH_ERR_INVALID_FORMAT;
2152 if ((tt = mktime(&tm)) < 0)
2153 return SSH_ERR_INVALID_FORMAT;
2154 /* success */
2155 *tp = (uint64_t)tt;
2156 return 0;
2157 }
2158
2159 void
format_absolute_time(uint64_t t,char * buf,size_t len)2160 format_absolute_time(uint64_t t, char *buf, size_t len)
2161 {
2162 time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */
2163 struct tm tm;
2164
2165 localtime_r(&tt, &tm);
2166 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
2167 }
2168
2169 /* check if path is absolute */
2170 int
path_absolute(const char * path)2171 path_absolute(const char *path)
2172 {
2173 return (*path == '/') ? 1 : 0;
2174 }
2175
2176 void
skip_space(char ** cpp)2177 skip_space(char **cpp)
2178 {
2179 char *cp;
2180
2181 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
2182 ;
2183 *cpp = cp;
2184 }
2185
2186 /* authorized_key-style options parsing helpers */
2187
2188 /*
2189 * Match flag 'opt' in *optsp, and if allow_negate is set then also match
2190 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0
2191 * if negated option matches.
2192 * If the option or negated option matches, then *optsp is updated to
2193 * point to the first character after the option.
2194 */
2195 int
opt_flag(const char * opt,int allow_negate,const char ** optsp)2196 opt_flag(const char *opt, int allow_negate, const char **optsp)
2197 {
2198 size_t opt_len = strlen(opt);
2199 const char *opts = *optsp;
2200 int negate = 0;
2201
2202 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) {
2203 opts += 3;
2204 negate = 1;
2205 }
2206 if (strncasecmp(opts, opt, opt_len) == 0) {
2207 *optsp = opts + opt_len;
2208 return negate ? 0 : 1;
2209 }
2210 return -1;
2211 }
2212
2213 char *
opt_dequote(const char ** sp,const char ** errstrp)2214 opt_dequote(const char **sp, const char **errstrp)
2215 {
2216 const char *s = *sp;
2217 char *ret;
2218 size_t i;
2219
2220 *errstrp = NULL;
2221 if (*s != '"') {
2222 *errstrp = "missing start quote";
2223 return NULL;
2224 }
2225 s++;
2226 if ((ret = malloc(strlen((s)) + 1)) == NULL) {
2227 *errstrp = "memory allocation failed";
2228 return NULL;
2229 }
2230 for (i = 0; *s != '\0' && *s != '"';) {
2231 if (s[0] == '\\' && s[1] == '"')
2232 s++;
2233 ret[i++] = *s++;
2234 }
2235 if (*s == '\0') {
2236 *errstrp = "missing end quote";
2237 free(ret);
2238 return NULL;
2239 }
2240 ret[i] = '\0';
2241 s++;
2242 *sp = s;
2243 return ret;
2244 }
2245
2246 int
opt_match(const char ** opts,const char * term)2247 opt_match(const char **opts, const char *term)
2248 {
2249 if (strncasecmp((*opts), term, strlen(term)) == 0 &&
2250 (*opts)[strlen(term)] == '=') {
2251 *opts += strlen(term) + 1;
2252 return 1;
2253 }
2254 return 0;
2255 }
2256
2257 sshsig_t
ssh_signal(int signum,sshsig_t handler)2258 ssh_signal(int signum, sshsig_t handler)
2259 {
2260 struct sigaction sa, osa;
2261
2262 /* mask all other signals while in handler */
2263 memset(&sa, 0, sizeof(sa));
2264 sa.sa_handler = handler;
2265 sigfillset(&sa.sa_mask);
2266 #if defined(SA_RESTART) && !defined(NO_SA_RESTART)
2267 if (signum != SIGALRM)
2268 sa.sa_flags = SA_RESTART;
2269 #endif
2270 if (sigaction(signum, &sa, &osa) == -1) {
2271 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno));
2272 return SIG_ERR;
2273 }
2274 return osa.sa_handler;
2275 }
2276