1 /* $OpenBSD: misc.c,v 1.193 2024/04/02 10:02:08 deraadt Exp $ */
2 /*
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Copyright (c) 2005-2020 Damien Miller. All rights reserved.
5 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20
21 #include <sys/types.h>
22 #include <sys/ioctl.h>
23 #include <sys/socket.h>
24 #include <sys/stat.h>
25 #include <sys/time.h>
26 #include <sys/wait.h>
27 #include <sys/un.h>
28
29 #include <net/if.h>
30 #include <netinet/in.h>
31 #include <netinet/ip.h>
32 #include <netinet/tcp.h>
33 #include <arpa/inet.h>
34
35 #include <ctype.h>
36 #include <errno.h>
37 #include <fcntl.h>
38 #include <netdb.h>
39 #include <paths.h>
40 #include <pwd.h>
41 #include <libgen.h>
42 #include <limits.h>
43 #include <nlist.h>
44 #include <poll.h>
45 #include <signal.h>
46 #include <stdarg.h>
47 #include <stdio.h>
48 #include <stdint.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52
53 #include "xmalloc.h"
54 #include "misc.h"
55 #include "log.h"
56 #include "ssh.h"
57 #include "sshbuf.h"
58 #include "ssherr.h"
59
60 /* remove newline at end of string */
61 char *
chop(char * s)62 chop(char *s)
63 {
64 char *t = s;
65 while (*t) {
66 if (*t == '\n' || *t == '\r') {
67 *t = '\0';
68 return s;
69 }
70 t++;
71 }
72 return s;
73
74 }
75
76 /* remove whitespace from end of string */
77 void
rtrim(char * s)78 rtrim(char *s)
79 {
80 size_t i;
81
82 if ((i = strlen(s)) == 0)
83 return;
84 for (i--; i > 0; i--) {
85 if (isspace((unsigned char)s[i]))
86 s[i] = '\0';
87 }
88 }
89
90 /* set/unset filedescriptor to non-blocking */
91 int
set_nonblock(int fd)92 set_nonblock(int fd)
93 {
94 int val;
95
96 val = fcntl(fd, F_GETFL);
97 if (val == -1) {
98 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
99 return (-1);
100 }
101 if (val & O_NONBLOCK) {
102 debug3("fd %d is O_NONBLOCK", fd);
103 return (0);
104 }
105 debug2("fd %d setting O_NONBLOCK", fd);
106 val |= O_NONBLOCK;
107 if (fcntl(fd, F_SETFL, val) == -1) {
108 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
109 strerror(errno));
110 return (-1);
111 }
112 return (0);
113 }
114
115 int
unset_nonblock(int fd)116 unset_nonblock(int fd)
117 {
118 int val;
119
120 val = fcntl(fd, F_GETFL);
121 if (val == -1) {
122 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
123 return (-1);
124 }
125 if (!(val & O_NONBLOCK)) {
126 debug3("fd %d is not O_NONBLOCK", fd);
127 return (0);
128 }
129 debug("fd %d clearing O_NONBLOCK", fd);
130 val &= ~O_NONBLOCK;
131 if (fcntl(fd, F_SETFL, val) == -1) {
132 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
133 fd, strerror(errno));
134 return (-1);
135 }
136 return (0);
137 }
138
139 const char *
ssh_gai_strerror(int gaierr)140 ssh_gai_strerror(int gaierr)
141 {
142 if (gaierr == EAI_SYSTEM && errno != 0)
143 return strerror(errno);
144 return gai_strerror(gaierr);
145 }
146
147 /* disable nagle on socket */
148 void
set_nodelay(int fd)149 set_nodelay(int fd)
150 {
151 int opt;
152 socklen_t optlen;
153
154 optlen = sizeof opt;
155 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
156 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
157 return;
158 }
159 if (opt == 1) {
160 debug2("fd %d is TCP_NODELAY", fd);
161 return;
162 }
163 opt = 1;
164 debug2("fd %d setting TCP_NODELAY", fd);
165 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
166 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
167 }
168
169 /* Allow local port reuse in TIME_WAIT */
170 int
set_reuseaddr(int fd)171 set_reuseaddr(int fd)
172 {
173 int on = 1;
174
175 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
176 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
177 return -1;
178 }
179 return 0;
180 }
181
182 /* Get/set routing domain */
183 char *
get_rdomain(int fd)184 get_rdomain(int fd)
185 {
186 int rtable;
187 char *ret;
188 socklen_t len = sizeof(rtable);
189
190 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) {
191 error("Failed to get routing domain for fd %d: %s",
192 fd, strerror(errno));
193 return NULL;
194 }
195 xasprintf(&ret, "%d", rtable);
196 return ret;
197 }
198
199 int
set_rdomain(int fd,const char * name)200 set_rdomain(int fd, const char *name)
201 {
202 int rtable;
203 const char *errstr;
204
205 if (name == NULL)
206 return 0; /* default table */
207
208 rtable = (int)strtonum(name, 0, 255, &errstr);
209 if (errstr != NULL) {
210 /* Shouldn't happen */
211 error("Invalid routing domain \"%s\": %s", name, errstr);
212 return -1;
213 }
214 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE,
215 &rtable, sizeof(rtable)) == -1) {
216 error("Failed to set routing domain %d on fd %d: %s",
217 rtable, fd, strerror(errno));
218 return -1;
219 }
220 return 0;
221 }
222
223 int
get_sock_af(int fd)224 get_sock_af(int fd)
225 {
226 struct sockaddr_storage to;
227 socklen_t tolen = sizeof(to);
228
229 memset(&to, 0, sizeof(to));
230 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1)
231 return -1;
232 return to.ss_family;
233 }
234
235 void
set_sock_tos(int fd,int tos)236 set_sock_tos(int fd, int tos)
237 {
238 int af;
239
240 switch ((af = get_sock_af(fd))) {
241 case -1:
242 /* assume not a socket */
243 break;
244 case AF_INET:
245 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos);
246 if (setsockopt(fd, IPPROTO_IP, IP_TOS,
247 &tos, sizeof(tos)) == -1) {
248 error("setsockopt socket %d IP_TOS %d: %s",
249 fd, tos, strerror(errno));
250 }
251 break;
252 case AF_INET6:
253 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos);
254 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS,
255 &tos, sizeof(tos)) == -1) {
256 error("setsockopt socket %d IPV6_TCLASS %d: %s",
257 fd, tos, strerror(errno));
258 }
259 break;
260 default:
261 debug2_f("unsupported socket family %d", af);
262 break;
263 }
264 }
265
266 /*
267 * Wait up to *timeoutp milliseconds for events on fd. Updates
268 * *timeoutp with time remaining.
269 * Returns 0 if fd ready or -1 on timeout or error (see errno).
270 */
271 static int
waitfd(int fd,int * timeoutp,short events,volatile sig_atomic_t * stop)272 waitfd(int fd, int *timeoutp, short events, volatile sig_atomic_t *stop)
273 {
274 struct pollfd pfd;
275 struct timespec timeout;
276 int oerrno, r;
277 sigset_t nsigset, osigset;
278
279 if (timeoutp && *timeoutp == -1)
280 timeoutp = NULL;
281 pfd.fd = fd;
282 pfd.events = events;
283 ptimeout_init(&timeout);
284 if (timeoutp != NULL)
285 ptimeout_deadline_ms(&timeout, *timeoutp);
286 if (stop != NULL)
287 sigfillset(&nsigset);
288 for (; timeoutp == NULL || *timeoutp >= 0;) {
289 if (stop != NULL) {
290 sigprocmask(SIG_BLOCK, &nsigset, &osigset);
291 if (*stop) {
292 sigprocmask(SIG_SETMASK, &osigset, NULL);
293 errno = EINTR;
294 return -1;
295 }
296 }
297 r = ppoll(&pfd, 1, ptimeout_get_tsp(&timeout),
298 stop != NULL ? &osigset : NULL);
299 oerrno = errno;
300 if (stop != NULL)
301 sigprocmask(SIG_SETMASK, &osigset, NULL);
302 if (timeoutp)
303 *timeoutp = ptimeout_get_ms(&timeout);
304 errno = oerrno;
305 if (r > 0)
306 return 0;
307 else if (r == -1 && errno != EAGAIN && errno != EINTR)
308 return -1;
309 else if (r == 0)
310 break;
311 }
312 /* timeout */
313 errno = ETIMEDOUT;
314 return -1;
315 }
316
317 /*
318 * Wait up to *timeoutp milliseconds for fd to be readable. Updates
319 * *timeoutp with time remaining.
320 * Returns 0 if fd ready or -1 on timeout or error (see errno).
321 */
322 int
waitrfd(int fd,int * timeoutp,volatile sig_atomic_t * stop)323 waitrfd(int fd, int *timeoutp, volatile sig_atomic_t *stop) {
324 return waitfd(fd, timeoutp, POLLIN, stop);
325 }
326
327 /*
328 * Attempt a non-blocking connect(2) to the specified address, waiting up to
329 * *timeoutp milliseconds for the connection to complete. If the timeout is
330 * <=0, then wait indefinitely.
331 *
332 * Returns 0 on success or -1 on failure.
333 */
334 int
timeout_connect(int sockfd,const struct sockaddr * serv_addr,socklen_t addrlen,int * timeoutp)335 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
336 socklen_t addrlen, int *timeoutp)
337 {
338 int optval = 0;
339 socklen_t optlen = sizeof(optval);
340
341 /* No timeout: just do a blocking connect() */
342 if (timeoutp == NULL || *timeoutp <= 0)
343 return connect(sockfd, serv_addr, addrlen);
344
345 set_nonblock(sockfd);
346 for (;;) {
347 if (connect(sockfd, serv_addr, addrlen) == 0) {
348 /* Succeeded already? */
349 unset_nonblock(sockfd);
350 return 0;
351 } else if (errno == EINTR)
352 continue;
353 else if (errno != EINPROGRESS)
354 return -1;
355 break;
356 }
357
358 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT, NULL) == -1)
359 return -1;
360
361 /* Completed or failed */
362 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) {
363 debug("getsockopt: %s", strerror(errno));
364 return -1;
365 }
366 if (optval != 0) {
367 errno = optval;
368 return -1;
369 }
370 unset_nonblock(sockfd);
371 return 0;
372 }
373
374 /* Characters considered whitespace in strsep calls. */
375 #define WHITESPACE " \t\r\n"
376 #define QUOTE "\""
377
378 /* return next token in configuration line */
379 static char *
strdelim_internal(char ** s,int split_equals)380 strdelim_internal(char **s, int split_equals)
381 {
382 char *old;
383 int wspace = 0;
384
385 if (*s == NULL)
386 return NULL;
387
388 old = *s;
389
390 *s = strpbrk(*s,
391 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE);
392 if (*s == NULL)
393 return (old);
394
395 if (*s[0] == '\"') {
396 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
397 /* Find matching quote */
398 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
399 return (NULL); /* no matching quote */
400 } else {
401 *s[0] = '\0';
402 *s += strspn(*s + 1, WHITESPACE) + 1;
403 return (old);
404 }
405 }
406
407 /* Allow only one '=' to be skipped */
408 if (split_equals && *s[0] == '=')
409 wspace = 1;
410 *s[0] = '\0';
411
412 /* Skip any extra whitespace after first token */
413 *s += strspn(*s + 1, WHITESPACE) + 1;
414 if (split_equals && *s[0] == '=' && !wspace)
415 *s += strspn(*s + 1, WHITESPACE) + 1;
416
417 return (old);
418 }
419
420 /*
421 * Return next token in configuration line; splts on whitespace or a
422 * single '=' character.
423 */
424 char *
strdelim(char ** s)425 strdelim(char **s)
426 {
427 return strdelim_internal(s, 1);
428 }
429
430 /*
431 * Return next token in configuration line; splts on whitespace only.
432 */
433 char *
strdelimw(char ** s)434 strdelimw(char **s)
435 {
436 return strdelim_internal(s, 0);
437 }
438
439 struct passwd *
pwcopy(struct passwd * pw)440 pwcopy(struct passwd *pw)
441 {
442 struct passwd *copy = xcalloc(1, sizeof(*copy));
443
444 copy->pw_name = xstrdup(pw->pw_name);
445 copy->pw_passwd = xstrdup(pw->pw_passwd);
446 copy->pw_gecos = xstrdup(pw->pw_gecos);
447 copy->pw_uid = pw->pw_uid;
448 copy->pw_gid = pw->pw_gid;
449 copy->pw_expire = pw->pw_expire;
450 copy->pw_change = pw->pw_change;
451 copy->pw_class = xstrdup(pw->pw_class);
452 copy->pw_dir = xstrdup(pw->pw_dir);
453 copy->pw_shell = xstrdup(pw->pw_shell);
454 return copy;
455 }
456
457 /*
458 * Convert ASCII string to TCP/IP port number.
459 * Port must be >=0 and <=65535.
460 * Return -1 if invalid.
461 */
462 int
a2port(const char * s)463 a2port(const char *s)
464 {
465 struct servent *se;
466 long long port;
467 const char *errstr;
468
469 port = strtonum(s, 0, 65535, &errstr);
470 if (errstr == NULL)
471 return (int)port;
472 if ((se = getservbyname(s, "tcp")) != NULL)
473 return ntohs(se->s_port);
474 return -1;
475 }
476
477 int
a2tun(const char * s,int * remote)478 a2tun(const char *s, int *remote)
479 {
480 const char *errstr = NULL;
481 char *sp, *ep;
482 int tun;
483
484 if (remote != NULL) {
485 *remote = SSH_TUNID_ANY;
486 sp = xstrdup(s);
487 if ((ep = strchr(sp, ':')) == NULL) {
488 free(sp);
489 return (a2tun(s, NULL));
490 }
491 ep[0] = '\0'; ep++;
492 *remote = a2tun(ep, NULL);
493 tun = a2tun(sp, NULL);
494 free(sp);
495 return (*remote == SSH_TUNID_ERR ? *remote : tun);
496 }
497
498 if (strcasecmp(s, "any") == 0)
499 return (SSH_TUNID_ANY);
500
501 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
502 if (errstr != NULL)
503 return (SSH_TUNID_ERR);
504
505 return (tun);
506 }
507
508 #define SECONDS 1
509 #define MINUTES (SECONDS * 60)
510 #define HOURS (MINUTES * 60)
511 #define DAYS (HOURS * 24)
512 #define WEEKS (DAYS * 7)
513
514 static char *
scandigits(char * s)515 scandigits(char *s)
516 {
517 while (isdigit((unsigned char)*s))
518 s++;
519 return s;
520 }
521
522 /*
523 * Convert a time string into seconds; format is
524 * a sequence of:
525 * time[qualifier]
526 *
527 * Valid time qualifiers are:
528 * <none> seconds
529 * s|S seconds
530 * m|M minutes
531 * h|H hours
532 * d|D days
533 * w|W weeks
534 *
535 * Examples:
536 * 90m 90 minutes
537 * 1h30m 90 minutes
538 * 2d 2 days
539 * 1w 1 week
540 *
541 * Return -1 if time string is invalid.
542 */
543 int
convtime(const char * s)544 convtime(const char *s)
545 {
546 int secs, total = 0, multiplier;
547 char *p, *os, *np, c;
548 const char *errstr;
549
550 if (s == NULL || *s == '\0')
551 return -1;
552 p = os = strdup(s); /* deal with const */
553 if (os == NULL)
554 return -1;
555
556 while (*p) {
557 np = scandigits(p);
558 if (np) {
559 c = *np;
560 *np = '\0';
561 }
562 secs = (int)strtonum(p, 0, INT_MAX, &errstr);
563 if (errstr)
564 goto fail;
565 *np = c;
566
567 multiplier = 1;
568 switch (c) {
569 case '\0':
570 np--; /* back up */
571 break;
572 case 's':
573 case 'S':
574 break;
575 case 'm':
576 case 'M':
577 multiplier = MINUTES;
578 break;
579 case 'h':
580 case 'H':
581 multiplier = HOURS;
582 break;
583 case 'd':
584 case 'D':
585 multiplier = DAYS;
586 break;
587 case 'w':
588 case 'W':
589 multiplier = WEEKS;
590 break;
591 default:
592 goto fail;
593 }
594 if (secs > INT_MAX / multiplier)
595 goto fail;
596 secs *= multiplier;
597 if (total > INT_MAX - secs)
598 goto fail;
599 total += secs;
600 if (total < 0)
601 goto fail;
602 p = ++np;
603 }
604 free(os);
605 return total;
606 fail:
607 free(os);
608 return -1;
609 }
610
611 #define TF_BUFS 8
612 #define TF_LEN 9
613
614 const char *
fmt_timeframe(time_t t)615 fmt_timeframe(time_t t)
616 {
617 char *buf;
618 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */
619 static int idx = 0;
620 unsigned int sec, min, hrs, day;
621 unsigned long long week;
622
623 buf = tfbuf[idx++];
624 if (idx == TF_BUFS)
625 idx = 0;
626
627 week = t;
628
629 sec = week % 60;
630 week /= 60;
631 min = week % 60;
632 week /= 60;
633 hrs = week % 24;
634 week /= 24;
635 day = week % 7;
636 week /= 7;
637
638 if (week > 0)
639 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs);
640 else if (day > 0)
641 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min);
642 else
643 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec);
644
645 return (buf);
646 }
647
648 /*
649 * Returns a standardized host+port identifier string.
650 * Caller must free returned string.
651 */
652 char *
put_host_port(const char * host,u_short port)653 put_host_port(const char *host, u_short port)
654 {
655 char *hoststr;
656
657 if (port == 0 || port == SSH_DEFAULT_PORT)
658 return(xstrdup(host));
659 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1)
660 fatal("put_host_port: asprintf: %s", strerror(errno));
661 debug3("put_host_port: %s", hoststr);
662 return hoststr;
663 }
664
665 /*
666 * Search for next delimiter between hostnames/addresses and ports.
667 * Argument may be modified (for termination).
668 * Returns *cp if parsing succeeds.
669 * *cp is set to the start of the next field, if one was found.
670 * The delimiter char, if present, is stored in delim.
671 * If this is the last field, *cp is set to NULL.
672 */
673 char *
hpdelim2(char ** cp,char * delim)674 hpdelim2(char **cp, char *delim)
675 {
676 char *s, *old;
677
678 if (cp == NULL || *cp == NULL)
679 return NULL;
680
681 old = s = *cp;
682 if (*s == '[') {
683 if ((s = strchr(s, ']')) == NULL)
684 return NULL;
685 else
686 s++;
687 } else if ((s = strpbrk(s, ":/")) == NULL)
688 s = *cp + strlen(*cp); /* skip to end (see first case below) */
689
690 switch (*s) {
691 case '\0':
692 *cp = NULL; /* no more fields*/
693 break;
694
695 case ':':
696 case '/':
697 if (delim != NULL)
698 *delim = *s;
699 *s = '\0'; /* terminate */
700 *cp = s + 1;
701 break;
702
703 default:
704 return NULL;
705 }
706
707 return old;
708 }
709
710 /* The common case: only accept colon as delimiter. */
711 char *
hpdelim(char ** cp)712 hpdelim(char **cp)
713 {
714 char *r, delim = '\0';
715
716 r = hpdelim2(cp, &delim);
717 if (delim == '/')
718 return NULL;
719 return r;
720 }
721
722 char *
cleanhostname(char * host)723 cleanhostname(char *host)
724 {
725 if (*host == '[' && host[strlen(host) - 1] == ']') {
726 host[strlen(host) - 1] = '\0';
727 return (host + 1);
728 } else
729 return host;
730 }
731
732 char *
colon(char * cp)733 colon(char *cp)
734 {
735 int flag = 0;
736
737 if (*cp == ':') /* Leading colon is part of file name. */
738 return NULL;
739 if (*cp == '[')
740 flag = 1;
741
742 for (; *cp; ++cp) {
743 if (*cp == '@' && *(cp+1) == '[')
744 flag = 1;
745 if (*cp == ']' && *(cp+1) == ':' && flag)
746 return (cp+1);
747 if (*cp == ':' && !flag)
748 return (cp);
749 if (*cp == '/')
750 return NULL;
751 }
752 return NULL;
753 }
754
755 /*
756 * Parse a [user@]host:[path] string.
757 * Caller must free returned user, host and path.
758 * Any of the pointer return arguments may be NULL (useful for syntax checking).
759 * If user was not specified then *userp will be set to NULL.
760 * If host was not specified then *hostp will be set to NULL.
761 * If path was not specified then *pathp will be set to ".".
762 * Returns 0 on success, -1 on failure.
763 */
764 int
parse_user_host_path(const char * s,char ** userp,char ** hostp,char ** pathp)765 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp)
766 {
767 char *user = NULL, *host = NULL, *path = NULL;
768 char *sdup, *tmp;
769 int ret = -1;
770
771 if (userp != NULL)
772 *userp = NULL;
773 if (hostp != NULL)
774 *hostp = NULL;
775 if (pathp != NULL)
776 *pathp = NULL;
777
778 sdup = xstrdup(s);
779
780 /* Check for remote syntax: [user@]host:[path] */
781 if ((tmp = colon(sdup)) == NULL)
782 goto out;
783
784 /* Extract optional path */
785 *tmp++ = '\0';
786 if (*tmp == '\0')
787 tmp = ".";
788 path = xstrdup(tmp);
789
790 /* Extract optional user and mandatory host */
791 tmp = strrchr(sdup, '@');
792 if (tmp != NULL) {
793 *tmp++ = '\0';
794 host = xstrdup(cleanhostname(tmp));
795 if (*sdup != '\0')
796 user = xstrdup(sdup);
797 } else {
798 host = xstrdup(cleanhostname(sdup));
799 user = NULL;
800 }
801
802 /* Success */
803 if (userp != NULL) {
804 *userp = user;
805 user = NULL;
806 }
807 if (hostp != NULL) {
808 *hostp = host;
809 host = NULL;
810 }
811 if (pathp != NULL) {
812 *pathp = path;
813 path = NULL;
814 }
815 ret = 0;
816 out:
817 free(sdup);
818 free(user);
819 free(host);
820 free(path);
821 return ret;
822 }
823
824 /*
825 * Parse a [user@]host[:port] string.
826 * Caller must free returned user and host.
827 * Any of the pointer return arguments may be NULL (useful for syntax checking).
828 * If user was not specified then *userp will be set to NULL.
829 * If port was not specified then *portp will be -1.
830 * Returns 0 on success, -1 on failure.
831 */
832 int
parse_user_host_port(const char * s,char ** userp,char ** hostp,int * portp)833 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
834 {
835 char *sdup, *cp, *tmp;
836 char *user = NULL, *host = NULL;
837 int port = -1, ret = -1;
838
839 if (userp != NULL)
840 *userp = NULL;
841 if (hostp != NULL)
842 *hostp = NULL;
843 if (portp != NULL)
844 *portp = -1;
845
846 if ((sdup = tmp = strdup(s)) == NULL)
847 return -1;
848 /* Extract optional username */
849 if ((cp = strrchr(tmp, '@')) != NULL) {
850 *cp = '\0';
851 if (*tmp == '\0')
852 goto out;
853 if ((user = strdup(tmp)) == NULL)
854 goto out;
855 tmp = cp + 1;
856 }
857 /* Extract mandatory hostname */
858 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0')
859 goto out;
860 host = xstrdup(cleanhostname(cp));
861 /* Convert and verify optional port */
862 if (tmp != NULL && *tmp != '\0') {
863 if ((port = a2port(tmp)) <= 0)
864 goto out;
865 }
866 /* Success */
867 if (userp != NULL) {
868 *userp = user;
869 user = NULL;
870 }
871 if (hostp != NULL) {
872 *hostp = host;
873 host = NULL;
874 }
875 if (portp != NULL)
876 *portp = port;
877 ret = 0;
878 out:
879 free(sdup);
880 free(user);
881 free(host);
882 return ret;
883 }
884
885 /*
886 * Converts a two-byte hex string to decimal.
887 * Returns the decimal value or -1 for invalid input.
888 */
889 static int
hexchar(const char * s)890 hexchar(const char *s)
891 {
892 unsigned char result[2];
893 int i;
894
895 for (i = 0; i < 2; i++) {
896 if (s[i] >= '0' && s[i] <= '9')
897 result[i] = (unsigned char)(s[i] - '0');
898 else if (s[i] >= 'a' && s[i] <= 'f')
899 result[i] = (unsigned char)(s[i] - 'a') + 10;
900 else if (s[i] >= 'A' && s[i] <= 'F')
901 result[i] = (unsigned char)(s[i] - 'A') + 10;
902 else
903 return -1;
904 }
905 return (result[0] << 4) | result[1];
906 }
907
908 /*
909 * Decode an url-encoded string.
910 * Returns a newly allocated string on success or NULL on failure.
911 */
912 static char *
urldecode(const char * src)913 urldecode(const char *src)
914 {
915 char *ret, *dst;
916 int ch;
917 size_t srclen;
918
919 if ((srclen = strlen(src)) >= SIZE_MAX)
920 fatal_f("input too large");
921 ret = xmalloc(srclen + 1);
922 for (dst = ret; *src != '\0'; src++) {
923 switch (*src) {
924 case '+':
925 *dst++ = ' ';
926 break;
927 case '%':
928 if (!isxdigit((unsigned char)src[1]) ||
929 !isxdigit((unsigned char)src[2]) ||
930 (ch = hexchar(src + 1)) == -1) {
931 free(ret);
932 return NULL;
933 }
934 *dst++ = ch;
935 src += 2;
936 break;
937 default:
938 *dst++ = *src;
939 break;
940 }
941 }
942 *dst = '\0';
943
944 return ret;
945 }
946
947 /*
948 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI.
949 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04
950 * Either user or path may be url-encoded (but not host or port).
951 * Caller must free returned user, host and path.
952 * Any of the pointer return arguments may be NULL (useful for syntax checking)
953 * but the scheme must always be specified.
954 * If user was not specified then *userp will be set to NULL.
955 * If port was not specified then *portp will be -1.
956 * If path was not specified then *pathp will be set to NULL.
957 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri.
958 */
959 int
parse_uri(const char * scheme,const char * uri,char ** userp,char ** hostp,int * portp,char ** pathp)960 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp,
961 int *portp, char **pathp)
962 {
963 char *uridup, *cp, *tmp, ch;
964 char *user = NULL, *host = NULL, *path = NULL;
965 int port = -1, ret = -1;
966 size_t len;
967
968 len = strlen(scheme);
969 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0)
970 return 1;
971 uri += len + 3;
972
973 if (userp != NULL)
974 *userp = NULL;
975 if (hostp != NULL)
976 *hostp = NULL;
977 if (portp != NULL)
978 *portp = -1;
979 if (pathp != NULL)
980 *pathp = NULL;
981
982 uridup = tmp = xstrdup(uri);
983
984 /* Extract optional ssh-info (username + connection params) */
985 if ((cp = strchr(tmp, '@')) != NULL) {
986 char *delim;
987
988 *cp = '\0';
989 /* Extract username and connection params */
990 if ((delim = strchr(tmp, ';')) != NULL) {
991 /* Just ignore connection params for now */
992 *delim = '\0';
993 }
994 if (*tmp == '\0') {
995 /* Empty username */
996 goto out;
997 }
998 if ((user = urldecode(tmp)) == NULL)
999 goto out;
1000 tmp = cp + 1;
1001 }
1002
1003 /* Extract mandatory hostname */
1004 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0')
1005 goto out;
1006 host = xstrdup(cleanhostname(cp));
1007 if (!valid_domain(host, 0, NULL))
1008 goto out;
1009
1010 if (tmp != NULL && *tmp != '\0') {
1011 if (ch == ':') {
1012 /* Convert and verify port. */
1013 if ((cp = strchr(tmp, '/')) != NULL)
1014 *cp = '\0';
1015 if ((port = a2port(tmp)) <= 0)
1016 goto out;
1017 tmp = cp ? cp + 1 : NULL;
1018 }
1019 if (tmp != NULL && *tmp != '\0') {
1020 /* Extract optional path */
1021 if ((path = urldecode(tmp)) == NULL)
1022 goto out;
1023 }
1024 }
1025
1026 /* Success */
1027 if (userp != NULL) {
1028 *userp = user;
1029 user = NULL;
1030 }
1031 if (hostp != NULL) {
1032 *hostp = host;
1033 host = NULL;
1034 }
1035 if (portp != NULL)
1036 *portp = port;
1037 if (pathp != NULL) {
1038 *pathp = path;
1039 path = NULL;
1040 }
1041 ret = 0;
1042 out:
1043 free(uridup);
1044 free(user);
1045 free(host);
1046 free(path);
1047 return ret;
1048 }
1049
1050 /* function to assist building execv() arguments */
1051 void
addargs(arglist * args,char * fmt,...)1052 addargs(arglist *args, char *fmt, ...)
1053 {
1054 va_list ap;
1055 char *cp;
1056 u_int nalloc;
1057 int r;
1058
1059 va_start(ap, fmt);
1060 r = vasprintf(&cp, fmt, ap);
1061 va_end(ap);
1062 if (r == -1)
1063 fatal_f("argument too long");
1064
1065 nalloc = args->nalloc;
1066 if (args->list == NULL) {
1067 nalloc = 32;
1068 args->num = 0;
1069 } else if (args->num > (256 * 1024))
1070 fatal_f("too many arguments");
1071 else if (args->num >= args->nalloc)
1072 fatal_f("arglist corrupt");
1073 else if (args->num+2 >= nalloc)
1074 nalloc *= 2;
1075
1076 args->list = xrecallocarray(args->list, args->nalloc,
1077 nalloc, sizeof(char *));
1078 args->nalloc = nalloc;
1079 args->list[args->num++] = cp;
1080 args->list[args->num] = NULL;
1081 }
1082
1083 void
replacearg(arglist * args,u_int which,char * fmt,...)1084 replacearg(arglist *args, u_int which, char *fmt, ...)
1085 {
1086 va_list ap;
1087 char *cp;
1088 int r;
1089
1090 va_start(ap, fmt);
1091 r = vasprintf(&cp, fmt, ap);
1092 va_end(ap);
1093 if (r == -1)
1094 fatal_f("argument too long");
1095 if (args->list == NULL || args->num >= args->nalloc)
1096 fatal_f("arglist corrupt");
1097
1098 if (which >= args->num)
1099 fatal_f("tried to replace invalid arg %d >= %d",
1100 which, args->num);
1101 free(args->list[which]);
1102 args->list[which] = cp;
1103 }
1104
1105 void
freeargs(arglist * args)1106 freeargs(arglist *args)
1107 {
1108 u_int i;
1109
1110 if (args == NULL)
1111 return;
1112 if (args->list != NULL && args->num < args->nalloc) {
1113 for (i = 0; i < args->num; i++)
1114 free(args->list[i]);
1115 free(args->list);
1116 }
1117 args->nalloc = args->num = 0;
1118 args->list = NULL;
1119 }
1120
1121 /*
1122 * Expands tildes in the file name. Returns data allocated by xmalloc.
1123 * Warning: this calls getpw*.
1124 */
1125 int
tilde_expand(const char * filename,uid_t uid,char ** retp)1126 tilde_expand(const char *filename, uid_t uid, char **retp)
1127 {
1128 char *ocopy = NULL, *copy, *s = NULL;
1129 const char *path = NULL, *user = NULL;
1130 struct passwd *pw;
1131 size_t len;
1132 int ret = -1, r, slash;
1133
1134 *retp = NULL;
1135 if (*filename != '~') {
1136 *retp = xstrdup(filename);
1137 return 0;
1138 }
1139 ocopy = copy = xstrdup(filename + 1);
1140
1141 if (*copy == '\0') /* ~ */
1142 path = NULL;
1143 else if (*copy == '/') {
1144 copy += strspn(copy, "/");
1145 if (*copy == '\0')
1146 path = NULL; /* ~/ */
1147 else
1148 path = copy; /* ~/path */
1149 } else {
1150 user = copy;
1151 if ((path = strchr(copy, '/')) != NULL) {
1152 copy[path - copy] = '\0';
1153 path++;
1154 path += strspn(path, "/");
1155 if (*path == '\0') /* ~user/ */
1156 path = NULL;
1157 /* else ~user/path */
1158 }
1159 /* else ~user */
1160 }
1161 if (user != NULL) {
1162 if ((pw = getpwnam(user)) == NULL) {
1163 error_f("No such user %s", user);
1164 goto out;
1165 }
1166 } else if ((pw = getpwuid(uid)) == NULL) {
1167 error_f("No such uid %ld", (long)uid);
1168 goto out;
1169 }
1170
1171 /* Make sure directory has a trailing '/' */
1172 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/';
1173
1174 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir,
1175 slash ? "/" : "", path != NULL ? path : "")) <= 0) {
1176 error_f("xasprintf failed");
1177 goto out;
1178 }
1179 if (r >= PATH_MAX) {
1180 error_f("Path too long");
1181 goto out;
1182 }
1183 /* success */
1184 ret = 0;
1185 *retp = s;
1186 s = NULL;
1187 out:
1188 free(s);
1189 free(ocopy);
1190 return ret;
1191 }
1192
1193 char *
tilde_expand_filename(const char * filename,uid_t uid)1194 tilde_expand_filename(const char *filename, uid_t uid)
1195 {
1196 char *ret;
1197
1198 if (tilde_expand(filename, uid, &ret) != 0)
1199 cleanup_exit(255);
1200 return ret;
1201 }
1202
1203 /*
1204 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT}
1205 * substitutions. A number of escapes may be specified as
1206 * (char *escape_chars, char *replacement) pairs. The list must be terminated
1207 * by a NULL escape_char. Returns replaced string in memory allocated by
1208 * xmalloc which the caller must free.
1209 */
1210 static char *
vdollar_percent_expand(int * parseerror,int dollar,int percent,const char * string,va_list ap)1211 vdollar_percent_expand(int *parseerror, int dollar, int percent,
1212 const char *string, va_list ap)
1213 {
1214 #define EXPAND_MAX_KEYS 64
1215 u_int num_keys = 0, i;
1216 struct {
1217 const char *key;
1218 const char *repl;
1219 } keys[EXPAND_MAX_KEYS];
1220 struct sshbuf *buf;
1221 int r, missingvar = 0;
1222 char *ret = NULL, *var, *varend, *val;
1223 size_t len;
1224
1225 if ((buf = sshbuf_new()) == NULL)
1226 fatal_f("sshbuf_new failed");
1227 if (parseerror == NULL)
1228 fatal_f("null parseerror arg");
1229 *parseerror = 1;
1230
1231 /* Gather keys if we're doing percent expansion. */
1232 if (percent) {
1233 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
1234 keys[num_keys].key = va_arg(ap, char *);
1235 if (keys[num_keys].key == NULL)
1236 break;
1237 keys[num_keys].repl = va_arg(ap, char *);
1238 if (keys[num_keys].repl == NULL) {
1239 fatal_f("NULL replacement for token %s",
1240 keys[num_keys].key);
1241 }
1242 }
1243 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
1244 fatal_f("too many keys");
1245 if (num_keys == 0)
1246 fatal_f("percent expansion without token list");
1247 }
1248
1249 /* Expand string */
1250 for (i = 0; *string != '\0'; string++) {
1251 /* Optionally process ${ENVIRONMENT} expansions. */
1252 if (dollar && string[0] == '$' && string[1] == '{') {
1253 string += 2; /* skip over '${' */
1254 if ((varend = strchr(string, '}')) == NULL) {
1255 error_f("environment variable '%s' missing "
1256 "closing '}'", string);
1257 goto out;
1258 }
1259 len = varend - string;
1260 if (len == 0) {
1261 error_f("zero-length environment variable");
1262 goto out;
1263 }
1264 var = xmalloc(len + 1);
1265 (void)strlcpy(var, string, len + 1);
1266 if ((val = getenv(var)) == NULL) {
1267 error_f("env var ${%s} has no value", var);
1268 missingvar = 1;
1269 } else {
1270 debug3_f("expand ${%s} -> '%s'", var, val);
1271 if ((r = sshbuf_put(buf, val, strlen(val))) !=0)
1272 fatal_fr(r, "sshbuf_put ${}");
1273 }
1274 free(var);
1275 string += len;
1276 continue;
1277 }
1278
1279 /*
1280 * Process percent expansions if we have a list of TOKENs.
1281 * If we're not doing percent expansion everything just gets
1282 * appended here.
1283 */
1284 if (*string != '%' || !percent) {
1285 append:
1286 if ((r = sshbuf_put_u8(buf, *string)) != 0)
1287 fatal_fr(r, "sshbuf_put_u8 %%");
1288 continue;
1289 }
1290 string++;
1291 /* %% case */
1292 if (*string == '%')
1293 goto append;
1294 if (*string == '\0') {
1295 error_f("invalid format");
1296 goto out;
1297 }
1298 for (i = 0; i < num_keys; i++) {
1299 if (strchr(keys[i].key, *string) != NULL) {
1300 if ((r = sshbuf_put(buf, keys[i].repl,
1301 strlen(keys[i].repl))) != 0)
1302 fatal_fr(r, "sshbuf_put %%-repl");
1303 break;
1304 }
1305 }
1306 if (i >= num_keys) {
1307 error_f("unknown key %%%c", *string);
1308 goto out;
1309 }
1310 }
1311 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL)
1312 fatal_f("sshbuf_dup_string failed");
1313 *parseerror = 0;
1314 out:
1315 sshbuf_free(buf);
1316 return *parseerror ? NULL : ret;
1317 #undef EXPAND_MAX_KEYS
1318 }
1319
1320 /*
1321 * Expand only environment variables.
1322 * Note that although this function is variadic like the other similar
1323 * functions, any such arguments will be unused.
1324 */
1325
1326 char *
dollar_expand(int * parseerr,const char * string,...)1327 dollar_expand(int *parseerr, const char *string, ...)
1328 {
1329 char *ret;
1330 int err;
1331 va_list ap;
1332
1333 va_start(ap, string);
1334 ret = vdollar_percent_expand(&err, 1, 0, string, ap);
1335 va_end(ap);
1336 if (parseerr != NULL)
1337 *parseerr = err;
1338 return ret;
1339 }
1340
1341 /*
1342 * Returns expanded string or NULL if a specified environment variable is
1343 * not defined, or calls fatal if the string is invalid.
1344 */
1345 char *
percent_expand(const char * string,...)1346 percent_expand(const char *string, ...)
1347 {
1348 char *ret;
1349 int err;
1350 va_list ap;
1351
1352 va_start(ap, string);
1353 ret = vdollar_percent_expand(&err, 0, 1, string, ap);
1354 va_end(ap);
1355 if (err)
1356 fatal_f("failed");
1357 return ret;
1358 }
1359
1360 /*
1361 * Returns expanded string or NULL if a specified environment variable is
1362 * not defined, or calls fatal if the string is invalid.
1363 */
1364 char *
percent_dollar_expand(const char * string,...)1365 percent_dollar_expand(const char *string, ...)
1366 {
1367 char *ret;
1368 int err;
1369 va_list ap;
1370
1371 va_start(ap, string);
1372 ret = vdollar_percent_expand(&err, 1, 1, string, ap);
1373 va_end(ap);
1374 if (err)
1375 fatal_f("failed");
1376 return ret;
1377 }
1378
1379 int
tun_open(int tun,int mode,char ** ifname)1380 tun_open(int tun, int mode, char **ifname)
1381 {
1382 struct ifreq ifr;
1383 char name[100];
1384 int fd = -1, sock;
1385 const char *tunbase = "tun";
1386
1387 if (ifname != NULL)
1388 *ifname = NULL;
1389
1390 if (mode == SSH_TUNMODE_ETHERNET)
1391 tunbase = "tap";
1392
1393 /* Open the tunnel device */
1394 if (tun <= SSH_TUNID_MAX) {
1395 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
1396 fd = open(name, O_RDWR);
1397 } else if (tun == SSH_TUNID_ANY) {
1398 for (tun = 100; tun >= 0; tun--) {
1399 snprintf(name, sizeof(name), "/dev/%s%d",
1400 tunbase, tun);
1401 if ((fd = open(name, O_RDWR)) >= 0)
1402 break;
1403 }
1404 } else {
1405 debug_f("invalid tunnel %u", tun);
1406 return -1;
1407 }
1408
1409 if (fd == -1) {
1410 debug_f("%s open: %s", name, strerror(errno));
1411 return -1;
1412 }
1413
1414 debug_f("%s mode %d fd %d", name, mode, fd);
1415
1416 /* Bring interface up if it is not already */
1417 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
1418 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1419 goto failed;
1420
1421 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
1422 debug_f("get interface %s flags: %s", ifr.ifr_name,
1423 strerror(errno));
1424 goto failed;
1425 }
1426
1427 if (!(ifr.ifr_flags & IFF_UP)) {
1428 ifr.ifr_flags |= IFF_UP;
1429 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
1430 debug_f("activate interface %s: %s", ifr.ifr_name,
1431 strerror(errno));
1432 goto failed;
1433 }
1434 }
1435
1436 if (ifname != NULL)
1437 *ifname = xstrdup(ifr.ifr_name);
1438
1439 close(sock);
1440 return fd;
1441
1442 failed:
1443 if (fd >= 0)
1444 close(fd);
1445 if (sock >= 0)
1446 close(sock);
1447 return -1;
1448 }
1449
1450 void
sanitise_stdfd(void)1451 sanitise_stdfd(void)
1452 {
1453 int nullfd, dupfd;
1454
1455 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1456 fprintf(stderr, "Couldn't open /dev/null: %s\n",
1457 strerror(errno));
1458 exit(1);
1459 }
1460 while (++dupfd <= STDERR_FILENO) {
1461 /* Only populate closed fds. */
1462 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
1463 if (dup2(nullfd, dupfd) == -1) {
1464 fprintf(stderr, "dup2: %s\n", strerror(errno));
1465 exit(1);
1466 }
1467 }
1468 }
1469 if (nullfd > STDERR_FILENO)
1470 close(nullfd);
1471 }
1472
1473 char *
tohex(const void * vp,size_t l)1474 tohex(const void *vp, size_t l)
1475 {
1476 const u_char *p = (const u_char *)vp;
1477 char b[3], *r;
1478 size_t i, hl;
1479
1480 if (l > 65536)
1481 return xstrdup("tohex: length > 65536");
1482
1483 hl = l * 2 + 1;
1484 r = xcalloc(1, hl);
1485 for (i = 0; i < l; i++) {
1486 snprintf(b, sizeof(b), "%02x", p[i]);
1487 strlcat(r, b, hl);
1488 }
1489 return (r);
1490 }
1491
1492 /*
1493 * Extend string *sp by the specified format. If *sp is not NULL (or empty),
1494 * then the separator 'sep' will be prepended before the formatted arguments.
1495 * Extended strings are heap allocated.
1496 */
1497 void
xextendf(char ** sp,const char * sep,const char * fmt,...)1498 xextendf(char **sp, const char *sep, const char *fmt, ...)
1499 {
1500 va_list ap;
1501 char *tmp1, *tmp2;
1502
1503 va_start(ap, fmt);
1504 xvasprintf(&tmp1, fmt, ap);
1505 va_end(ap);
1506
1507 if (*sp == NULL || **sp == '\0') {
1508 free(*sp);
1509 *sp = tmp1;
1510 return;
1511 }
1512 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1);
1513 free(tmp1);
1514 free(*sp);
1515 *sp = tmp2;
1516 }
1517
1518
1519 u_int64_t
get_u64(const void * vp)1520 get_u64(const void *vp)
1521 {
1522 const u_char *p = (const u_char *)vp;
1523 u_int64_t v;
1524
1525 v = (u_int64_t)p[0] << 56;
1526 v |= (u_int64_t)p[1] << 48;
1527 v |= (u_int64_t)p[2] << 40;
1528 v |= (u_int64_t)p[3] << 32;
1529 v |= (u_int64_t)p[4] << 24;
1530 v |= (u_int64_t)p[5] << 16;
1531 v |= (u_int64_t)p[6] << 8;
1532 v |= (u_int64_t)p[7];
1533
1534 return (v);
1535 }
1536
1537 u_int32_t
get_u32(const void * vp)1538 get_u32(const void *vp)
1539 {
1540 const u_char *p = (const u_char *)vp;
1541 u_int32_t v;
1542
1543 v = (u_int32_t)p[0] << 24;
1544 v |= (u_int32_t)p[1] << 16;
1545 v |= (u_int32_t)p[2] << 8;
1546 v |= (u_int32_t)p[3];
1547
1548 return (v);
1549 }
1550
1551 u_int32_t
get_u32_le(const void * vp)1552 get_u32_le(const void *vp)
1553 {
1554 const u_char *p = (const u_char *)vp;
1555 u_int32_t v;
1556
1557 v = (u_int32_t)p[0];
1558 v |= (u_int32_t)p[1] << 8;
1559 v |= (u_int32_t)p[2] << 16;
1560 v |= (u_int32_t)p[3] << 24;
1561
1562 return (v);
1563 }
1564
1565 u_int16_t
get_u16(const void * vp)1566 get_u16(const void *vp)
1567 {
1568 const u_char *p = (const u_char *)vp;
1569 u_int16_t v;
1570
1571 v = (u_int16_t)p[0] << 8;
1572 v |= (u_int16_t)p[1];
1573
1574 return (v);
1575 }
1576
1577 void
put_u64(void * vp,u_int64_t v)1578 put_u64(void *vp, u_int64_t v)
1579 {
1580 u_char *p = (u_char *)vp;
1581
1582 p[0] = (u_char)(v >> 56) & 0xff;
1583 p[1] = (u_char)(v >> 48) & 0xff;
1584 p[2] = (u_char)(v >> 40) & 0xff;
1585 p[3] = (u_char)(v >> 32) & 0xff;
1586 p[4] = (u_char)(v >> 24) & 0xff;
1587 p[5] = (u_char)(v >> 16) & 0xff;
1588 p[6] = (u_char)(v >> 8) & 0xff;
1589 p[7] = (u_char)v & 0xff;
1590 }
1591
1592 void
put_u32(void * vp,u_int32_t v)1593 put_u32(void *vp, u_int32_t v)
1594 {
1595 u_char *p = (u_char *)vp;
1596
1597 p[0] = (u_char)(v >> 24) & 0xff;
1598 p[1] = (u_char)(v >> 16) & 0xff;
1599 p[2] = (u_char)(v >> 8) & 0xff;
1600 p[3] = (u_char)v & 0xff;
1601 }
1602
1603 void
put_u32_le(void * vp,u_int32_t v)1604 put_u32_le(void *vp, u_int32_t v)
1605 {
1606 u_char *p = (u_char *)vp;
1607
1608 p[0] = (u_char)v & 0xff;
1609 p[1] = (u_char)(v >> 8) & 0xff;
1610 p[2] = (u_char)(v >> 16) & 0xff;
1611 p[3] = (u_char)(v >> 24) & 0xff;
1612 }
1613
1614 void
put_u16(void * vp,u_int16_t v)1615 put_u16(void *vp, u_int16_t v)
1616 {
1617 u_char *p = (u_char *)vp;
1618
1619 p[0] = (u_char)(v >> 8) & 0xff;
1620 p[1] = (u_char)v & 0xff;
1621 }
1622
1623 void
ms_subtract_diff(struct timeval * start,int * ms)1624 ms_subtract_diff(struct timeval *start, int *ms)
1625 {
1626 struct timeval diff, finish;
1627
1628 monotime_tv(&finish);
1629 timersub(&finish, start, &diff);
1630 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
1631 }
1632
1633 void
ms_to_timespec(struct timespec * ts,int ms)1634 ms_to_timespec(struct timespec *ts, int ms)
1635 {
1636 if (ms < 0)
1637 ms = 0;
1638 ts->tv_sec = ms / 1000;
1639 ts->tv_nsec = (ms % 1000) * 1000 * 1000;
1640 }
1641
1642 void
monotime_ts(struct timespec * ts)1643 monotime_ts(struct timespec *ts)
1644 {
1645 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0)
1646 fatal("clock_gettime: %s", strerror(errno));
1647 }
1648
1649 void
monotime_tv(struct timeval * tv)1650 monotime_tv(struct timeval *tv)
1651 {
1652 struct timespec ts;
1653
1654 monotime_ts(&ts);
1655 tv->tv_sec = ts.tv_sec;
1656 tv->tv_usec = ts.tv_nsec / 1000;
1657 }
1658
1659 time_t
monotime(void)1660 monotime(void)
1661 {
1662 struct timespec ts;
1663
1664 monotime_ts(&ts);
1665 return (ts.tv_sec);
1666 }
1667
1668 double
monotime_double(void)1669 monotime_double(void)
1670 {
1671 struct timespec ts;
1672
1673 monotime_ts(&ts);
1674 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0;
1675 }
1676
1677 void
bandwidth_limit_init(struct bwlimit * bw,u_int64_t kbps,size_t buflen)1678 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
1679 {
1680 bw->buflen = buflen;
1681 bw->rate = kbps;
1682 bw->thresh = buflen;
1683 bw->lamt = 0;
1684 timerclear(&bw->bwstart);
1685 timerclear(&bw->bwend);
1686 }
1687
1688 /* Callback from read/write loop to insert bandwidth-limiting delays */
1689 void
bandwidth_limit(struct bwlimit * bw,size_t read_len)1690 bandwidth_limit(struct bwlimit *bw, size_t read_len)
1691 {
1692 u_int64_t waitlen;
1693 struct timespec ts, rm;
1694
1695 bw->lamt += read_len;
1696 if (!timerisset(&bw->bwstart)) {
1697 monotime_tv(&bw->bwstart);
1698 return;
1699 }
1700 if (bw->lamt < bw->thresh)
1701 return;
1702
1703 monotime_tv(&bw->bwend);
1704 timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
1705 if (!timerisset(&bw->bwend))
1706 return;
1707
1708 bw->lamt *= 8;
1709 waitlen = (double)1000000L * bw->lamt / bw->rate;
1710
1711 bw->bwstart.tv_sec = waitlen / 1000000L;
1712 bw->bwstart.tv_usec = waitlen % 1000000L;
1713
1714 if (timercmp(&bw->bwstart, &bw->bwend, >)) {
1715 timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
1716
1717 /* Adjust the wait time */
1718 if (bw->bwend.tv_sec) {
1719 bw->thresh /= 2;
1720 if (bw->thresh < bw->buflen / 4)
1721 bw->thresh = bw->buflen / 4;
1722 } else if (bw->bwend.tv_usec < 10000) {
1723 bw->thresh *= 2;
1724 if (bw->thresh > bw->buflen * 8)
1725 bw->thresh = bw->buflen * 8;
1726 }
1727
1728 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
1729 while (nanosleep(&ts, &rm) == -1) {
1730 if (errno != EINTR)
1731 break;
1732 ts = rm;
1733 }
1734 }
1735
1736 bw->lamt = 0;
1737 monotime_tv(&bw->bwstart);
1738 }
1739
1740 /* Make a template filename for mk[sd]temp() */
1741 void
mktemp_proto(char * s,size_t len)1742 mktemp_proto(char *s, size_t len)
1743 {
1744 const char *tmpdir;
1745 int r;
1746
1747 if ((tmpdir = getenv("TMPDIR")) != NULL) {
1748 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
1749 if (r > 0 && (size_t)r < len)
1750 return;
1751 }
1752 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
1753 if (r < 0 || (size_t)r >= len)
1754 fatal_f("template string too short");
1755 }
1756
1757 static const struct {
1758 const char *name;
1759 int value;
1760 } ipqos[] = {
1761 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */
1762 { "af11", IPTOS_DSCP_AF11 },
1763 { "af12", IPTOS_DSCP_AF12 },
1764 { "af13", IPTOS_DSCP_AF13 },
1765 { "af21", IPTOS_DSCP_AF21 },
1766 { "af22", IPTOS_DSCP_AF22 },
1767 { "af23", IPTOS_DSCP_AF23 },
1768 { "af31", IPTOS_DSCP_AF31 },
1769 { "af32", IPTOS_DSCP_AF32 },
1770 { "af33", IPTOS_DSCP_AF33 },
1771 { "af41", IPTOS_DSCP_AF41 },
1772 { "af42", IPTOS_DSCP_AF42 },
1773 { "af43", IPTOS_DSCP_AF43 },
1774 { "cs0", IPTOS_DSCP_CS0 },
1775 { "cs1", IPTOS_DSCP_CS1 },
1776 { "cs2", IPTOS_DSCP_CS2 },
1777 { "cs3", IPTOS_DSCP_CS3 },
1778 { "cs4", IPTOS_DSCP_CS4 },
1779 { "cs5", IPTOS_DSCP_CS5 },
1780 { "cs6", IPTOS_DSCP_CS6 },
1781 { "cs7", IPTOS_DSCP_CS7 },
1782 { "ef", IPTOS_DSCP_EF },
1783 { "le", IPTOS_DSCP_LE },
1784 { "lowdelay", IPTOS_LOWDELAY },
1785 { "throughput", IPTOS_THROUGHPUT },
1786 { "reliability", IPTOS_RELIABILITY },
1787 { NULL, -1 }
1788 };
1789
1790 int
parse_ipqos(const char * cp)1791 parse_ipqos(const char *cp)
1792 {
1793 const char *errstr;
1794 u_int i;
1795 int val;
1796
1797 if (cp == NULL)
1798 return -1;
1799 for (i = 0; ipqos[i].name != NULL; i++) {
1800 if (strcasecmp(cp, ipqos[i].name) == 0)
1801 return ipqos[i].value;
1802 }
1803 /* Try parsing as an integer */
1804 val = (int)strtonum(cp, 0, 255, &errstr);
1805 if (errstr)
1806 return -1;
1807 return val;
1808 }
1809
1810 const char *
iptos2str(int iptos)1811 iptos2str(int iptos)
1812 {
1813 int i;
1814 static char iptos_str[sizeof "0xff"];
1815
1816 for (i = 0; ipqos[i].name != NULL; i++) {
1817 if (ipqos[i].value == iptos)
1818 return ipqos[i].name;
1819 }
1820 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1821 return iptos_str;
1822 }
1823
1824 void
lowercase(char * s)1825 lowercase(char *s)
1826 {
1827 for (; *s; s++)
1828 *s = tolower((u_char)*s);
1829 }
1830
1831 int
unix_listener(const char * path,int backlog,int unlink_first)1832 unix_listener(const char *path, int backlog, int unlink_first)
1833 {
1834 struct sockaddr_un sunaddr;
1835 int saved_errno, sock;
1836
1837 memset(&sunaddr, 0, sizeof(sunaddr));
1838 sunaddr.sun_family = AF_UNIX;
1839 if (strlcpy(sunaddr.sun_path, path,
1840 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1841 error_f("path \"%s\" too long for Unix domain socket", path);
1842 errno = ENAMETOOLONG;
1843 return -1;
1844 }
1845
1846 sock = socket(PF_UNIX, SOCK_STREAM, 0);
1847 if (sock == -1) {
1848 saved_errno = errno;
1849 error_f("socket: %.100s", strerror(errno));
1850 errno = saved_errno;
1851 return -1;
1852 }
1853 if (unlink_first == 1) {
1854 if (unlink(path) != 0 && errno != ENOENT)
1855 error("unlink(%s): %.100s", path, strerror(errno));
1856 }
1857 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
1858 saved_errno = errno;
1859 error_f("cannot bind to path %s: %s", path, strerror(errno));
1860 close(sock);
1861 errno = saved_errno;
1862 return -1;
1863 }
1864 if (listen(sock, backlog) == -1) {
1865 saved_errno = errno;
1866 error_f("cannot listen on path %s: %s", path, strerror(errno));
1867 close(sock);
1868 unlink(path);
1869 errno = saved_errno;
1870 return -1;
1871 }
1872 return sock;
1873 }
1874
1875 /*
1876 * Compares two strings that maybe be NULL. Returns non-zero if strings
1877 * are both NULL or are identical, returns zero otherwise.
1878 */
1879 static int
strcmp_maybe_null(const char * a,const char * b)1880 strcmp_maybe_null(const char *a, const char *b)
1881 {
1882 if ((a == NULL && b != NULL) || (a != NULL && b == NULL))
1883 return 0;
1884 if (a != NULL && strcmp(a, b) != 0)
1885 return 0;
1886 return 1;
1887 }
1888
1889 /*
1890 * Compare two forwards, returning non-zero if they are identical or
1891 * zero otherwise.
1892 */
1893 int
forward_equals(const struct Forward * a,const struct Forward * b)1894 forward_equals(const struct Forward *a, const struct Forward *b)
1895 {
1896 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0)
1897 return 0;
1898 if (a->listen_port != b->listen_port)
1899 return 0;
1900 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0)
1901 return 0;
1902 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0)
1903 return 0;
1904 if (a->connect_port != b->connect_port)
1905 return 0;
1906 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0)
1907 return 0;
1908 /* allocated_port and handle are not checked */
1909 return 1;
1910 }
1911
1912 /* returns 1 if process is already daemonized, 0 otherwise */
1913 int
daemonized(void)1914 daemonized(void)
1915 {
1916 int fd;
1917
1918 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
1919 close(fd);
1920 return 0; /* have controlling terminal */
1921 }
1922 if (getppid() != 1)
1923 return 0; /* parent is not init */
1924 if (getsid(0) != getpid())
1925 return 0; /* not session leader */
1926 debug3("already daemonized");
1927 return 1;
1928 }
1929
1930 /*
1931 * Splits 's' into an argument vector. Handles quoted string and basic
1932 * escape characters (\\, \", \'). Caller must free the argument vector
1933 * and its members.
1934 */
1935 int
argv_split(const char * s,int * argcp,char *** argvp,int terminate_on_comment)1936 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment)
1937 {
1938 int r = SSH_ERR_INTERNAL_ERROR;
1939 int argc = 0, quote, i, j;
1940 char *arg, **argv = xcalloc(1, sizeof(*argv));
1941
1942 *argvp = NULL;
1943 *argcp = 0;
1944
1945 for (i = 0; s[i] != '\0'; i++) {
1946 /* Skip leading whitespace */
1947 if (s[i] == ' ' || s[i] == '\t')
1948 continue;
1949 if (terminate_on_comment && s[i] == '#')
1950 break;
1951 /* Start of a token */
1952 quote = 0;
1953
1954 argv = xreallocarray(argv, (argc + 2), sizeof(*argv));
1955 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1);
1956 argv[argc] = NULL;
1957
1958 /* Copy the token in, removing escapes */
1959 for (j = 0; s[i] != '\0'; i++) {
1960 if (s[i] == '\\') {
1961 if (s[i + 1] == '\'' ||
1962 s[i + 1] == '\"' ||
1963 s[i + 1] == '\\' ||
1964 (quote == 0 && s[i + 1] == ' ')) {
1965 i++; /* Skip '\' */
1966 arg[j++] = s[i];
1967 } else {
1968 /* Unrecognised escape */
1969 arg[j++] = s[i];
1970 }
1971 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t'))
1972 break; /* done */
1973 else if (quote == 0 && (s[i] == '\"' || s[i] == '\''))
1974 quote = s[i]; /* quote start */
1975 else if (quote != 0 && s[i] == quote)
1976 quote = 0; /* quote end */
1977 else
1978 arg[j++] = s[i];
1979 }
1980 if (s[i] == '\0') {
1981 if (quote != 0) {
1982 /* Ran out of string looking for close quote */
1983 r = SSH_ERR_INVALID_FORMAT;
1984 goto out;
1985 }
1986 break;
1987 }
1988 }
1989 /* Success */
1990 *argcp = argc;
1991 *argvp = argv;
1992 argc = 0;
1993 argv = NULL;
1994 r = 0;
1995 out:
1996 if (argc != 0 && argv != NULL) {
1997 for (i = 0; i < argc; i++)
1998 free(argv[i]);
1999 free(argv);
2000 }
2001 return r;
2002 }
2003
2004 /*
2005 * Reassemble an argument vector into a string, quoting and escaping as
2006 * necessary. Caller must free returned string.
2007 */
2008 char *
argv_assemble(int argc,char ** argv)2009 argv_assemble(int argc, char **argv)
2010 {
2011 int i, j, ws, r;
2012 char c, *ret;
2013 struct sshbuf *buf, *arg;
2014
2015 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL)
2016 fatal_f("sshbuf_new failed");
2017
2018 for (i = 0; i < argc; i++) {
2019 ws = 0;
2020 sshbuf_reset(arg);
2021 for (j = 0; argv[i][j] != '\0'; j++) {
2022 r = 0;
2023 c = argv[i][j];
2024 switch (c) {
2025 case ' ':
2026 case '\t':
2027 ws = 1;
2028 r = sshbuf_put_u8(arg, c);
2029 break;
2030 case '\\':
2031 case '\'':
2032 case '"':
2033 if ((r = sshbuf_put_u8(arg, '\\')) != 0)
2034 break;
2035 /* FALLTHROUGH */
2036 default:
2037 r = sshbuf_put_u8(arg, c);
2038 break;
2039 }
2040 if (r != 0)
2041 fatal_fr(r, "sshbuf_put_u8");
2042 }
2043 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) ||
2044 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) ||
2045 (r = sshbuf_putb(buf, arg)) != 0 ||
2046 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0))
2047 fatal_fr(r, "assemble");
2048 }
2049 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL)
2050 fatal_f("malloc failed");
2051 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf));
2052 ret[sshbuf_len(buf)] = '\0';
2053 sshbuf_free(buf);
2054 sshbuf_free(arg);
2055 return ret;
2056 }
2057
2058 char *
argv_next(int * argcp,char *** argvp)2059 argv_next(int *argcp, char ***argvp)
2060 {
2061 char *ret = (*argvp)[0];
2062
2063 if (*argcp > 0 && ret != NULL) {
2064 (*argcp)--;
2065 (*argvp)++;
2066 }
2067 return ret;
2068 }
2069
2070 void
argv_consume(int * argcp)2071 argv_consume(int *argcp)
2072 {
2073 *argcp = 0;
2074 }
2075
2076 void
argv_free(char ** av,int ac)2077 argv_free(char **av, int ac)
2078 {
2079 int i;
2080
2081 if (av == NULL)
2082 return;
2083 for (i = 0; i < ac; i++)
2084 free(av[i]);
2085 free(av);
2086 }
2087
2088 /* Returns 0 if pid exited cleanly, non-zero otherwise */
2089 int
exited_cleanly(pid_t pid,const char * tag,const char * cmd,int quiet)2090 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)
2091 {
2092 int status;
2093
2094 while (waitpid(pid, &status, 0) == -1) {
2095 if (errno != EINTR) {
2096 error("%s waitpid: %s", tag, strerror(errno));
2097 return -1;
2098 }
2099 }
2100 if (WIFSIGNALED(status)) {
2101 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status));
2102 return -1;
2103 } else if (WEXITSTATUS(status) != 0) {
2104 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO,
2105 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status));
2106 return -1;
2107 }
2108 return 0;
2109 }
2110
2111 /*
2112 * Check a given path for security. This is defined as all components
2113 * of the path to the file must be owned by either the owner of
2114 * of the file or root and no directories must be group or world writable.
2115 *
2116 * XXX Should any specific check be done for sym links ?
2117 *
2118 * Takes a file name, its stat information (preferably from fstat() to
2119 * avoid races), the uid of the expected owner, their home directory and an
2120 * error buffer plus max size as arguments.
2121 *
2122 * Returns 0 on success and -1 on failure
2123 */
2124 int
safe_path(const char * name,struct stat * stp,const char * pw_dir,uid_t uid,char * err,size_t errlen)2125 safe_path(const char *name, struct stat *stp, const char *pw_dir,
2126 uid_t uid, char *err, size_t errlen)
2127 {
2128 char buf[PATH_MAX], homedir[PATH_MAX];
2129 char *cp;
2130 int comparehome = 0;
2131 struct stat st;
2132
2133 if (realpath(name, buf) == NULL) {
2134 snprintf(err, errlen, "realpath %s failed: %s", name,
2135 strerror(errno));
2136 return -1;
2137 }
2138 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
2139 comparehome = 1;
2140
2141 if (!S_ISREG(stp->st_mode)) {
2142 snprintf(err, errlen, "%s is not a regular file", buf);
2143 return -1;
2144 }
2145 if ((stp->st_uid != 0 && stp->st_uid != uid) ||
2146 (stp->st_mode & 022) != 0) {
2147 snprintf(err, errlen, "bad ownership or modes for file %s",
2148 buf);
2149 return -1;
2150 }
2151
2152 /* for each component of the canonical path, walking upwards */
2153 for (;;) {
2154 if ((cp = dirname(buf)) == NULL) {
2155 snprintf(err, errlen, "dirname() failed");
2156 return -1;
2157 }
2158 strlcpy(buf, cp, sizeof(buf));
2159
2160 if (stat(buf, &st) == -1 ||
2161 (st.st_uid != 0 && st.st_uid != uid) ||
2162 (st.st_mode & 022) != 0) {
2163 snprintf(err, errlen,
2164 "bad ownership or modes for directory %s", buf);
2165 return -1;
2166 }
2167
2168 /* If are past the homedir then we can stop */
2169 if (comparehome && strcmp(homedir, buf) == 0)
2170 break;
2171
2172 /*
2173 * dirname should always complete with a "/" path,
2174 * but we can be paranoid and check for "." too
2175 */
2176 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
2177 break;
2178 }
2179 return 0;
2180 }
2181
2182 /*
2183 * Version of safe_path() that accepts an open file descriptor to
2184 * avoid races.
2185 *
2186 * Returns 0 on success and -1 on failure
2187 */
2188 int
safe_path_fd(int fd,const char * file,struct passwd * pw,char * err,size_t errlen)2189 safe_path_fd(int fd, const char *file, struct passwd *pw,
2190 char *err, size_t errlen)
2191 {
2192 struct stat st;
2193
2194 /* check the open file to avoid races */
2195 if (fstat(fd, &st) == -1) {
2196 snprintf(err, errlen, "cannot stat file %s: %s",
2197 file, strerror(errno));
2198 return -1;
2199 }
2200 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
2201 }
2202
2203 /*
2204 * Sets the value of the given variable in the environment. If the variable
2205 * already exists, its value is overridden.
2206 */
2207 void
child_set_env(char *** envp,u_int * envsizep,const char * name,const char * value)2208 child_set_env(char ***envp, u_int *envsizep, const char *name,
2209 const char *value)
2210 {
2211 char **env;
2212 u_int envsize;
2213 u_int i, namelen;
2214
2215 if (strchr(name, '=') != NULL) {
2216 error("Invalid environment variable \"%.100s\"", name);
2217 return;
2218 }
2219
2220 /*
2221 * Find the slot where the value should be stored. If the variable
2222 * already exists, we reuse the slot; otherwise we append a new slot
2223 * at the end of the array, expanding if necessary.
2224 */
2225 env = *envp;
2226 namelen = strlen(name);
2227 for (i = 0; env[i]; i++)
2228 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
2229 break;
2230 if (env[i]) {
2231 /* Reuse the slot. */
2232 free(env[i]);
2233 } else {
2234 /* New variable. Expand if necessary. */
2235 envsize = *envsizep;
2236 if (i >= envsize - 1) {
2237 if (envsize >= 1000)
2238 fatal("child_set_env: too many env vars");
2239 envsize += 50;
2240 env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
2241 *envsizep = envsize;
2242 }
2243 /* Need to set the NULL pointer at end of array beyond the new slot. */
2244 env[i + 1] = NULL;
2245 }
2246
2247 /* Allocate space and format the variable in the appropriate slot. */
2248 /* XXX xasprintf */
2249 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
2250 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
2251 }
2252
2253 /*
2254 * Check and optionally lowercase a domain name, also removes trailing '.'
2255 * Returns 1 on success and 0 on failure, storing an error message in errstr.
2256 */
2257 int
valid_domain(char * name,int makelower,const char ** errstr)2258 valid_domain(char *name, int makelower, const char **errstr)
2259 {
2260 size_t i, l = strlen(name);
2261 u_char c, last = '\0';
2262 static char errbuf[256];
2263
2264 if (l == 0) {
2265 strlcpy(errbuf, "empty domain name", sizeof(errbuf));
2266 goto bad;
2267 }
2268 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) {
2269 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" "
2270 "starts with invalid character", name);
2271 goto bad;
2272 }
2273 for (i = 0; i < l; i++) {
2274 c = tolower((u_char)name[i]);
2275 if (makelower)
2276 name[i] = (char)c;
2277 if (last == '.' && c == '.') {
2278 snprintf(errbuf, sizeof(errbuf), "domain name "
2279 "\"%.100s\" contains consecutive separators", name);
2280 goto bad;
2281 }
2282 if (c != '.' && c != '-' && !isalnum(c) &&
2283 c != '_') /* technically invalid, but common */ {
2284 snprintf(errbuf, sizeof(errbuf), "domain name "
2285 "\"%.100s\" contains invalid characters", name);
2286 goto bad;
2287 }
2288 last = c;
2289 }
2290 if (name[l - 1] == '.')
2291 name[l - 1] = '\0';
2292 if (errstr != NULL)
2293 *errstr = NULL;
2294 return 1;
2295 bad:
2296 if (errstr != NULL)
2297 *errstr = errbuf;
2298 return 0;
2299 }
2300
2301 /*
2302 * Verify that a environment variable name (not including initial '$') is
2303 * valid; consisting of one or more alphanumeric or underscore characters only.
2304 * Returns 1 on valid, 0 otherwise.
2305 */
2306 int
valid_env_name(const char * name)2307 valid_env_name(const char *name)
2308 {
2309 const char *cp;
2310
2311 if (name[0] == '\0')
2312 return 0;
2313 for (cp = name; *cp != '\0'; cp++) {
2314 if (!isalnum((u_char)*cp) && *cp != '_')
2315 return 0;
2316 }
2317 return 1;
2318 }
2319
2320 const char *
atoi_err(const char * nptr,int * val)2321 atoi_err(const char *nptr, int *val)
2322 {
2323 const char *errstr = NULL;
2324
2325 if (nptr == NULL || *nptr == '\0')
2326 return "missing";
2327 *val = strtonum(nptr, 0, INT_MAX, &errstr);
2328 return errstr;
2329 }
2330
2331 int
parse_absolute_time(const char * s,uint64_t * tp)2332 parse_absolute_time(const char *s, uint64_t *tp)
2333 {
2334 struct tm tm;
2335 time_t tt;
2336 char buf[32], *fmt;
2337 const char *cp;
2338 size_t l;
2339 int is_utc = 0;
2340
2341 *tp = 0;
2342
2343 l = strlen(s);
2344 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) {
2345 is_utc = 1;
2346 l--;
2347 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) {
2348 is_utc = 1;
2349 l -= 3;
2350 }
2351 /*
2352 * POSIX strptime says "The application shall ensure that there
2353 * is white-space or other non-alphanumeric characters between
2354 * any two conversion specifications" so arrange things this way.
2355 */
2356 switch (l) {
2357 case 8: /* YYYYMMDD */
2358 fmt = "%Y-%m-%d";
2359 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
2360 break;
2361 case 12: /* YYYYMMDDHHMM */
2362 fmt = "%Y-%m-%dT%H:%M";
2363 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s",
2364 s, s + 4, s + 6, s + 8, s + 10);
2365 break;
2366 case 14: /* YYYYMMDDHHMMSS */
2367 fmt = "%Y-%m-%dT%H:%M:%S";
2368 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
2369 s, s + 4, s + 6, s + 8, s + 10, s + 12);
2370 break;
2371 default:
2372 return SSH_ERR_INVALID_FORMAT;
2373 }
2374
2375 memset(&tm, 0, sizeof(tm));
2376 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0')
2377 return SSH_ERR_INVALID_FORMAT;
2378 if (is_utc) {
2379 if ((tt = timegm(&tm)) < 0)
2380 return SSH_ERR_INVALID_FORMAT;
2381 } else {
2382 if ((tt = mktime(&tm)) < 0)
2383 return SSH_ERR_INVALID_FORMAT;
2384 }
2385 /* success */
2386 *tp = (uint64_t)tt;
2387 return 0;
2388 }
2389
2390 void
format_absolute_time(uint64_t t,char * buf,size_t len)2391 format_absolute_time(uint64_t t, char *buf, size_t len)
2392 {
2393 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t;
2394 struct tm tm;
2395
2396 localtime_r(&tt, &tm);
2397 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
2398 }
2399
2400 /*
2401 * Parse a "pattern=interval" clause (e.g. a ChannelTimeout).
2402 * Returns 0 on success or non-zero on failure.
2403 * Caller must free *typep.
2404 */
2405 int
parse_pattern_interval(const char * s,char ** typep,int * secsp)2406 parse_pattern_interval(const char *s, char **typep, int *secsp)
2407 {
2408 char *cp, *sdup;
2409 int secs;
2410
2411 if (typep != NULL)
2412 *typep = NULL;
2413 if (secsp != NULL)
2414 *secsp = 0;
2415 if (s == NULL)
2416 return -1;
2417 sdup = xstrdup(s);
2418
2419 if ((cp = strchr(sdup, '=')) == NULL || cp == sdup) {
2420 free(sdup);
2421 return -1;
2422 }
2423 *cp++ = '\0';
2424 if ((secs = convtime(cp)) < 0) {
2425 free(sdup);
2426 return -1;
2427 }
2428 /* success */
2429 if (typep != NULL)
2430 *typep = xstrdup(sdup);
2431 if (secsp != NULL)
2432 *secsp = secs;
2433 free(sdup);
2434 return 0;
2435 }
2436
2437 /* check if path is absolute */
2438 int
path_absolute(const char * path)2439 path_absolute(const char *path)
2440 {
2441 return (*path == '/') ? 1 : 0;
2442 }
2443
2444 void
skip_space(char ** cpp)2445 skip_space(char **cpp)
2446 {
2447 char *cp;
2448
2449 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
2450 ;
2451 *cpp = cp;
2452 }
2453
2454 /* authorized_key-style options parsing helpers */
2455
2456 /*
2457 * Match flag 'opt' in *optsp, and if allow_negate is set then also match
2458 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0
2459 * if negated option matches.
2460 * If the option or negated option matches, then *optsp is updated to
2461 * point to the first character after the option.
2462 */
2463 int
opt_flag(const char * opt,int allow_negate,const char ** optsp)2464 opt_flag(const char *opt, int allow_negate, const char **optsp)
2465 {
2466 size_t opt_len = strlen(opt);
2467 const char *opts = *optsp;
2468 int negate = 0;
2469
2470 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) {
2471 opts += 3;
2472 negate = 1;
2473 }
2474 if (strncasecmp(opts, opt, opt_len) == 0) {
2475 *optsp = opts + opt_len;
2476 return negate ? 0 : 1;
2477 }
2478 return -1;
2479 }
2480
2481 char *
opt_dequote(const char ** sp,const char ** errstrp)2482 opt_dequote(const char **sp, const char **errstrp)
2483 {
2484 const char *s = *sp;
2485 char *ret;
2486 size_t i;
2487
2488 *errstrp = NULL;
2489 if (*s != '"') {
2490 *errstrp = "missing start quote";
2491 return NULL;
2492 }
2493 s++;
2494 if ((ret = malloc(strlen((s)) + 1)) == NULL) {
2495 *errstrp = "memory allocation failed";
2496 return NULL;
2497 }
2498 for (i = 0; *s != '\0' && *s != '"';) {
2499 if (s[0] == '\\' && s[1] == '"')
2500 s++;
2501 ret[i++] = *s++;
2502 }
2503 if (*s == '\0') {
2504 *errstrp = "missing end quote";
2505 free(ret);
2506 return NULL;
2507 }
2508 ret[i] = '\0';
2509 s++;
2510 *sp = s;
2511 return ret;
2512 }
2513
2514 int
opt_match(const char ** opts,const char * term)2515 opt_match(const char **opts, const char *term)
2516 {
2517 if (strncasecmp((*opts), term, strlen(term)) == 0 &&
2518 (*opts)[strlen(term)] == '=') {
2519 *opts += strlen(term) + 1;
2520 return 1;
2521 }
2522 return 0;
2523 }
2524
2525 void
opt_array_append2(const char * file,const int line,const char * directive,char *** array,int ** iarray,u_int * lp,const char * s,int i)2526 opt_array_append2(const char *file, const int line, const char *directive,
2527 char ***array, int **iarray, u_int *lp, const char *s, int i)
2528 {
2529
2530 if (*lp >= INT_MAX)
2531 fatal("%s line %d: Too many %s entries", file, line, directive);
2532
2533 if (iarray != NULL) {
2534 *iarray = xrecallocarray(*iarray, *lp, *lp + 1,
2535 sizeof(**iarray));
2536 (*iarray)[*lp] = i;
2537 }
2538
2539 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array));
2540 (*array)[*lp] = xstrdup(s);
2541 (*lp)++;
2542 }
2543
2544 void
opt_array_append(const char * file,const int line,const char * directive,char *** array,u_int * lp,const char * s)2545 opt_array_append(const char *file, const int line, const char *directive,
2546 char ***array, u_int *lp, const char *s)
2547 {
2548 opt_array_append2(file, line, directive, array, NULL, lp, s, 0);
2549 }
2550
2551 void
opt_array_free2(char ** array,int ** iarray,u_int l)2552 opt_array_free2(char **array, int **iarray, u_int l)
2553 {
2554 u_int i;
2555
2556 if (array == NULL || l == 0)
2557 return;
2558 for (i = 0; i < l; i++)
2559 free(array[i]);
2560 free(array);
2561 free(iarray);
2562 }
2563
2564 sshsig_t
ssh_signal(int signum,sshsig_t handler)2565 ssh_signal(int signum, sshsig_t handler)
2566 {
2567 struct sigaction sa, osa;
2568
2569 /* mask all other signals while in handler */
2570 memset(&sa, 0, sizeof(sa));
2571 sa.sa_handler = handler;
2572 sigfillset(&sa.sa_mask);
2573 if (signum != SIGALRM)
2574 sa.sa_flags = SA_RESTART;
2575 if (sigaction(signum, &sa, &osa) == -1) {
2576 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno));
2577 return SIG_ERR;
2578 }
2579 return osa.sa_handler;
2580 }
2581
2582 int
stdfd_devnull(int do_stdin,int do_stdout,int do_stderr)2583 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr)
2584 {
2585 int devnull, ret = 0;
2586
2587 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
2588 error_f("open %s: %s", _PATH_DEVNULL,
2589 strerror(errno));
2590 return -1;
2591 }
2592 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) ||
2593 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) ||
2594 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) {
2595 error_f("dup2: %s", strerror(errno));
2596 ret = -1;
2597 }
2598 if (devnull > STDERR_FILENO)
2599 close(devnull);
2600 return ret;
2601 }
2602
2603 /*
2604 * Runs command in a subprocess with a minimal environment.
2605 * Returns pid on success, 0 on failure.
2606 * The child stdout and stderr maybe captured, left attached or sent to
2607 * /dev/null depending on the contents of flags.
2608 * "tag" is prepended to log messages.
2609 * NB. "command" is only used for logging; the actual command executed is
2610 * av[0].
2611 */
2612 pid_t
subprocess(const char * tag,const char * command,int ac,char ** av,FILE ** child,u_int flags,struct passwd * pw,privdrop_fn * drop_privs,privrestore_fn * restore_privs)2613 subprocess(const char *tag, const char *command,
2614 int ac, char **av, FILE **child, u_int flags,
2615 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs)
2616 {
2617 FILE *f = NULL;
2618 struct stat st;
2619 int fd, devnull, p[2], i;
2620 pid_t pid;
2621 char *cp, errmsg[512];
2622 u_int nenv = 0;
2623 char **env = NULL;
2624
2625 /* If dropping privs, then must specify user and restore function */
2626 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) {
2627 error("%s: inconsistent arguments", tag); /* XXX fatal? */
2628 return 0;
2629 }
2630 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) {
2631 error("%s: no user for current uid", tag);
2632 return 0;
2633 }
2634 if (child != NULL)
2635 *child = NULL;
2636
2637 debug3_f("%s command \"%s\" running as %s (flags 0x%x)",
2638 tag, command, pw->pw_name, flags);
2639
2640 /* Check consistency */
2641 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
2642 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) {
2643 error_f("inconsistent flags");
2644 return 0;
2645 }
2646 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) {
2647 error_f("inconsistent flags/output");
2648 return 0;
2649 }
2650
2651 /*
2652 * If executing an explicit binary, then verify the it exists
2653 * and appears safe-ish to execute
2654 */
2655 if (!path_absolute(av[0])) {
2656 error("%s path is not absolute", tag);
2657 return 0;
2658 }
2659 if (drop_privs != NULL)
2660 drop_privs(pw);
2661 if (stat(av[0], &st) == -1) {
2662 error("Could not stat %s \"%s\": %s", tag,
2663 av[0], strerror(errno));
2664 goto restore_return;
2665 }
2666 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 &&
2667 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) {
2668 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg);
2669 goto restore_return;
2670 }
2671 /* Prepare to keep the child's stdout if requested */
2672 if (pipe(p) == -1) {
2673 error("%s: pipe: %s", tag, strerror(errno));
2674 restore_return:
2675 if (restore_privs != NULL)
2676 restore_privs();
2677 return 0;
2678 }
2679 if (restore_privs != NULL)
2680 restore_privs();
2681
2682 switch ((pid = fork())) {
2683 case -1: /* error */
2684 error("%s: fork: %s", tag, strerror(errno));
2685 close(p[0]);
2686 close(p[1]);
2687 return 0;
2688 case 0: /* child */
2689 /* Prepare a minimal environment for the child. */
2690 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) {
2691 nenv = 5;
2692 env = xcalloc(sizeof(*env), nenv);
2693 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH);
2694 child_set_env(&env, &nenv, "USER", pw->pw_name);
2695 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name);
2696 child_set_env(&env, &nenv, "HOME", pw->pw_dir);
2697 if ((cp = getenv("LANG")) != NULL)
2698 child_set_env(&env, &nenv, "LANG", cp);
2699 }
2700
2701 for (i = 1; i < NSIG; i++)
2702 ssh_signal(i, SIG_DFL);
2703
2704 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
2705 error("%s: open %s: %s", tag, _PATH_DEVNULL,
2706 strerror(errno));
2707 _exit(1);
2708 }
2709 if (dup2(devnull, STDIN_FILENO) == -1) {
2710 error("%s: dup2: %s", tag, strerror(errno));
2711 _exit(1);
2712 }
2713
2714 /* Set up stdout as requested; leave stderr in place for now. */
2715 fd = -1;
2716 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0)
2717 fd = p[1];
2718 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0)
2719 fd = devnull;
2720 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) {
2721 error("%s: dup2: %s", tag, strerror(errno));
2722 _exit(1);
2723 }
2724 closefrom(STDERR_FILENO + 1);
2725
2726 if (geteuid() == 0 &&
2727 initgroups(pw->pw_name, pw->pw_gid) == -1) {
2728 error("%s: initgroups(%s, %u): %s", tag,
2729 pw->pw_name, (u_int)pw->pw_gid, strerror(errno));
2730 _exit(1);
2731 }
2732 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) {
2733 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
2734 strerror(errno));
2735 _exit(1);
2736 }
2737 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) {
2738 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid,
2739 strerror(errno));
2740 _exit(1);
2741 }
2742 /* stdin is pointed to /dev/null at this point */
2743 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
2744 dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
2745 error("%s: dup2: %s", tag, strerror(errno));
2746 _exit(1);
2747 }
2748 if (env != NULL)
2749 execve(av[0], av, env);
2750 else
2751 execv(av[0], av);
2752 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve",
2753 command, strerror(errno));
2754 _exit(127);
2755 default: /* parent */
2756 break;
2757 }
2758
2759 close(p[1]);
2760 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0)
2761 close(p[0]);
2762 else if ((f = fdopen(p[0], "r")) == NULL) {
2763 error("%s: fdopen: %s", tag, strerror(errno));
2764 close(p[0]);
2765 /* Don't leave zombie child */
2766 kill(pid, SIGTERM);
2767 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
2768 ;
2769 return 0;
2770 }
2771 /* Success */
2772 debug3_f("%s pid %ld", tag, (long)pid);
2773 if (child != NULL)
2774 *child = f;
2775 return pid;
2776 }
2777
2778 const char *
lookup_env_in_list(const char * env,char * const * envs,size_t nenvs)2779 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs)
2780 {
2781 size_t i, envlen;
2782
2783 envlen = strlen(env);
2784 for (i = 0; i < nenvs; i++) {
2785 if (strncmp(envs[i], env, envlen) == 0 &&
2786 envs[i][envlen] == '=') {
2787 return envs[i] + envlen + 1;
2788 }
2789 }
2790 return NULL;
2791 }
2792
2793 const char *
lookup_setenv_in_list(const char * env,char * const * envs,size_t nenvs)2794 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs)
2795 {
2796 char *name, *cp;
2797 const char *ret;
2798
2799 name = xstrdup(env);
2800 if ((cp = strchr(name, '=')) == NULL) {
2801 free(name);
2802 return NULL; /* not env=val */
2803 }
2804 *cp = '\0';
2805 ret = lookup_env_in_list(name, envs, nenvs);
2806 free(name);
2807 return ret;
2808 }
2809
2810 /*
2811 * Helpers for managing poll(2)/ppoll(2) timeouts
2812 * Will remember the earliest deadline and return it for use in poll/ppoll.
2813 */
2814
2815 /* Initialise a poll/ppoll timeout with an indefinite deadline */
2816 void
ptimeout_init(struct timespec * pt)2817 ptimeout_init(struct timespec *pt)
2818 {
2819 /*
2820 * Deliberately invalid for ppoll(2).
2821 * Will be converted to NULL in ptimeout_get_tspec() later.
2822 */
2823 pt->tv_sec = -1;
2824 pt->tv_nsec = 0;
2825 }
2826
2827 /* Specify a poll/ppoll deadline of at most 'sec' seconds */
2828 void
ptimeout_deadline_sec(struct timespec * pt,long sec)2829 ptimeout_deadline_sec(struct timespec *pt, long sec)
2830 {
2831 if (pt->tv_sec == -1 || pt->tv_sec >= sec) {
2832 pt->tv_sec = sec;
2833 pt->tv_nsec = 0;
2834 }
2835 }
2836
2837 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */
2838 static void
ptimeout_deadline_tsp(struct timespec * pt,struct timespec * p)2839 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p)
2840 {
2841 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=))
2842 *pt = *p;
2843 }
2844
2845 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */
2846 void
ptimeout_deadline_ms(struct timespec * pt,long ms)2847 ptimeout_deadline_ms(struct timespec *pt, long ms)
2848 {
2849 struct timespec p;
2850
2851 p.tv_sec = ms / 1000;
2852 p.tv_nsec = (ms % 1000) * 1000000;
2853 ptimeout_deadline_tsp(pt, &p);
2854 }
2855
2856 /* Specify a poll/ppoll deadline at wall clock monotime 'when' (timespec) */
2857 void
ptimeout_deadline_monotime_tsp(struct timespec * pt,struct timespec * when)2858 ptimeout_deadline_monotime_tsp(struct timespec *pt, struct timespec *when)
2859 {
2860 struct timespec now, t;
2861
2862 monotime_ts(&now);
2863
2864 if (timespeccmp(&now, when, >=)) {
2865 /* 'when' is now or in the past. Timeout ASAP */
2866 pt->tv_sec = 0;
2867 pt->tv_nsec = 0;
2868 } else {
2869 timespecsub(when, &now, &t);
2870 ptimeout_deadline_tsp(pt, &t);
2871 }
2872 }
2873
2874 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */
2875 void
ptimeout_deadline_monotime(struct timespec * pt,time_t when)2876 ptimeout_deadline_monotime(struct timespec *pt, time_t when)
2877 {
2878 struct timespec t;
2879
2880 t.tv_sec = when;
2881 t.tv_nsec = 0;
2882 ptimeout_deadline_monotime_tsp(pt, &t);
2883 }
2884
2885 /* Get a poll(2) timeout value in milliseconds */
2886 int
ptimeout_get_ms(struct timespec * pt)2887 ptimeout_get_ms(struct timespec *pt)
2888 {
2889 if (pt->tv_sec == -1)
2890 return -1;
2891 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000)
2892 return INT_MAX;
2893 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000);
2894 }
2895
2896 /* Get a ppoll(2) timeout value as a timespec pointer */
2897 struct timespec *
ptimeout_get_tsp(struct timespec * pt)2898 ptimeout_get_tsp(struct timespec *pt)
2899 {
2900 return pt->tv_sec == -1 ? NULL : pt;
2901 }
2902
2903 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */
2904 int
ptimeout_isset(struct timespec * pt)2905 ptimeout_isset(struct timespec *pt)
2906 {
2907 return pt->tv_sec != -1;
2908 }
2909
2910 /*
2911 * Returns zero if the library at 'path' contains symbol 's', nonzero
2912 * otherwise.
2913 */
2914 int
lib_contains_symbol(const char * path,const char * s)2915 lib_contains_symbol(const char *path, const char *s)
2916 {
2917 struct nlist nl[2];
2918 int ret = -1, r;
2919
2920 memset(nl, 0, sizeof(nl));
2921 nl[0].n_name = xstrdup(s);
2922 nl[1].n_name = NULL;
2923 if ((r = nlist(path, nl)) == -1) {
2924 error_f("nlist failed for %s", path);
2925 goto out;
2926 }
2927 if (r != 0 || nl[0].n_value == 0 || nl[0].n_type == 0) {
2928 error_f("library %s does not contain symbol %s", path, s);
2929 goto out;
2930 }
2931 /* success */
2932 ret = 0;
2933 out:
2934 free(nl[0].n_name);
2935 return ret;
2936 }
2937