1 /* $OpenBSD: misc.c,v 1.181 2023/03/03 02:37:58 dtucker Exp $ */
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>
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.
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.
23 #include <sys/types.h>
24 #include <sys/ioctl.h>
25 #include <sys/socket.h>
46 #include <netinet/in.h>
47 #include <netinet/in_systm.h>
48 #include <netinet/ip.h>
49 #include <netinet/tcp.h>
50 #include <arpa/inet.h>
61 #ifdef SSH_TUN_OPENBSD
73 /* remove newline at end of string */
79 if (*t == '\n' || *t == '\r') {
89 /* remove whitespace from end of string */
95 if ((i = strlen(s)) == 0)
97 for (i--; i > 0; i--) {
98 if (isspace((unsigned char)s[i]))
103 /* set/unset filedescriptor to non-blocking */
109 val = fcntl(fd, F_GETFL);
111 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
114 if (val & O_NONBLOCK) {
115 debug3("fd %d is O_NONBLOCK", fd);
118 debug2("fd %d setting O_NONBLOCK", fd);
120 if (fcntl(fd, F_SETFL, val) == -1) {
121 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd,
129 unset_nonblock(int fd)
133 val = fcntl(fd, F_GETFL);
135 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno));
138 if (!(val & O_NONBLOCK)) {
139 debug3("fd %d is not O_NONBLOCK", fd);
142 debug("fd %d clearing O_NONBLOCK", fd);
144 if (fcntl(fd, F_SETFL, val) == -1) {
145 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s",
146 fd, strerror(errno));
153 ssh_gai_strerror(int gaierr)
155 if (gaierr == EAI_SYSTEM && errno != 0)
156 return strerror(errno);
157 return gai_strerror(gaierr);
160 /* disable nagle on socket */
168 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) {
169 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno));
173 debug2("fd %d is TCP_NODELAY", fd);
177 debug2("fd %d setting TCP_NODELAY", fd);
178 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1)
179 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
182 /* Allow local port reuse in TIME_WAIT */
184 set_reuseaddr(int fd)
188 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
189 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
195 /* Get/set routing domain */
199 #if defined(HAVE_SYS_GET_RDOMAIN)
200 return sys_get_rdomain(fd);
201 #elif defined(__OpenBSD__)
204 socklen_t len = sizeof(rtable);
206 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) {
207 error("Failed to get routing domain for fd %d: %s",
208 fd, strerror(errno));
211 xasprintf(&ret, "%d", rtable);
213 #else /* defined(__OpenBSD__) */
219 set_rdomain(int fd, const char *name)
221 #if defined(HAVE_SYS_SET_RDOMAIN)
222 return sys_set_rdomain(fd, name);
223 #elif defined(__OpenBSD__)
228 return 0; /* default table */
230 rtable = (int)strtonum(name, 0, 255, &errstr);
231 if (errstr != NULL) {
232 /* Shouldn't happen */
233 error("Invalid routing domain \"%s\": %s", name, errstr);
236 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE,
237 &rtable, sizeof(rtable)) == -1) {
238 error("Failed to set routing domain %d on fd %d: %s",
239 rtable, fd, strerror(errno));
243 #else /* defined(__OpenBSD__) */
244 error("Setting routing domain is not supported on this platform");
252 struct sockaddr_storage to;
253 socklen_t tolen = sizeof(to);
255 memset(&to, 0, sizeof(to));
256 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1)
259 if (to.ss_family == AF_INET6 &&
260 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
267 set_sock_tos(int fd, int tos)
269 #ifndef IP_TOS_IS_BROKEN
272 switch ((af = get_sock_af(fd))) {
274 /* assume not a socket */
278 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos);
279 if (setsockopt(fd, IPPROTO_IP, IP_TOS,
280 &tos, sizeof(tos)) == -1) {
281 error("setsockopt socket %d IP_TOS %d: %s",
282 fd, tos, strerror(errno));
288 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos);
289 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS,
290 &tos, sizeof(tos)) == -1) {
291 error("setsockopt socket %d IPV6_TCLASS %d: %s",
292 fd, tos, strerror(errno));
294 # endif /* IPV6_TCLASS */
297 debug2_f("unsupported socket family %d", af);
300 #endif /* IP_TOS_IS_BROKEN */
304 * Wait up to *timeoutp milliseconds for events on fd. Updates
305 * *timeoutp with time remaining.
306 * Returns 0 if fd ready or -1 on timeout or error (see errno).
309 waitfd(int fd, int *timeoutp, short events)
312 struct timeval t_start;
317 for (; *timeoutp >= 0;) {
318 monotime_tv(&t_start);
319 r = poll(&pfd, 1, *timeoutp);
321 ms_subtract_diff(&t_start, timeoutp);
325 else if (r == -1 && errno != EAGAIN && errno != EINTR)
336 * Wait up to *timeoutp milliseconds for fd to be readable. Updates
337 * *timeoutp with time remaining.
338 * Returns 0 if fd ready or -1 on timeout or error (see errno).
341 waitrfd(int fd, int *timeoutp) {
342 return waitfd(fd, timeoutp, POLLIN);
346 * Attempt a non-blocking connect(2) to the specified address, waiting up to
347 * *timeoutp milliseconds for the connection to complete. If the timeout is
348 * <=0, then wait indefinitely.
350 * Returns 0 on success or -1 on failure.
353 timeout_connect(int sockfd, const struct sockaddr *serv_addr,
354 socklen_t addrlen, int *timeoutp)
357 socklen_t optlen = sizeof(optval);
359 /* No timeout: just do a blocking connect() */
360 if (timeoutp == NULL || *timeoutp <= 0)
361 return connect(sockfd, serv_addr, addrlen);
363 set_nonblock(sockfd);
365 if (connect(sockfd, serv_addr, addrlen) == 0) {
366 /* Succeeded already? */
367 unset_nonblock(sockfd);
369 } else if (errno == EINTR)
371 else if (errno != EINPROGRESS)
376 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1)
379 /* Completed or failed */
380 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) {
381 debug("getsockopt: %s", strerror(errno));
388 unset_nonblock(sockfd);
392 /* Characters considered whitespace in strsep calls. */
393 #define WHITESPACE " \t\r\n"
396 /* return next token in configuration line */
398 strdelim_internal(char **s, int split_equals)
409 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE);
414 memmove(*s, *s + 1, strlen(*s)); /* move nul too */
415 /* Find matching quote */
416 if ((*s = strpbrk(*s, QUOTE)) == NULL) {
417 return (NULL); /* no matching quote */
420 *s += strspn(*s + 1, WHITESPACE) + 1;
425 /* Allow only one '=' to be skipped */
426 if (split_equals && *s[0] == '=')
430 /* Skip any extra whitespace after first token */
431 *s += strspn(*s + 1, WHITESPACE) + 1;
432 if (split_equals && *s[0] == '=' && !wspace)
433 *s += strspn(*s + 1, WHITESPACE) + 1;
439 * Return next token in configuration line; splts on whitespace or a
440 * single '=' character.
445 return strdelim_internal(s, 1);
449 * Return next token in configuration line; splts on whitespace only.
454 return strdelim_internal(s, 0);
458 pwcopy(struct passwd *pw)
460 struct passwd *copy = xcalloc(1, sizeof(*copy));
462 copy->pw_name = xstrdup(pw->pw_name);
463 copy->pw_passwd = xstrdup(pw->pw_passwd == NULL ? "*" : pw->pw_passwd);
464 #ifdef HAVE_STRUCT_PASSWD_PW_GECOS
465 copy->pw_gecos = xstrdup(pw->pw_gecos);
467 copy->pw_uid = pw->pw_uid;
468 copy->pw_gid = pw->pw_gid;
469 #ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE
470 copy->pw_expire = pw->pw_expire;
472 #ifdef HAVE_STRUCT_PASSWD_PW_CHANGE
473 copy->pw_change = pw->pw_change;
475 #ifdef HAVE_STRUCT_PASSWD_PW_CLASS
476 copy->pw_class = xstrdup(pw->pw_class);
478 copy->pw_dir = xstrdup(pw->pw_dir);
479 copy->pw_shell = xstrdup(pw->pw_shell);
484 * Convert ASCII string to TCP/IP port number.
485 * Port must be >=0 and <=65535.
486 * Return -1 if invalid.
489 a2port(const char *s)
495 port = strtonum(s, 0, 65535, &errstr);
498 if ((se = getservbyname(s, "tcp")) != NULL)
499 return ntohs(se->s_port);
504 a2tun(const char *s, int *remote)
506 const char *errstr = NULL;
510 if (remote != NULL) {
511 *remote = SSH_TUNID_ANY;
513 if ((ep = strchr(sp, ':')) == NULL) {
515 return (a2tun(s, NULL));
518 *remote = a2tun(ep, NULL);
519 tun = a2tun(sp, NULL);
521 return (*remote == SSH_TUNID_ERR ? *remote : tun);
524 if (strcasecmp(s, "any") == 0)
525 return (SSH_TUNID_ANY);
527 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr);
529 return (SSH_TUNID_ERR);
535 #define MINUTES (SECONDS * 60)
536 #define HOURS (MINUTES * 60)
537 #define DAYS (HOURS * 24)
538 #define WEEKS (DAYS * 7)
541 * Convert a time string into seconds; format is
545 * Valid time qualifiers are:
559 * Return -1 if time string is invalid.
562 convtime(const char *s)
564 long total, secs, multiplier;
572 if (p == NULL || *p == '\0')
576 secs = strtol(p, &endp, 10);
578 (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) ||
592 multiplier = MINUTES;
609 if (secs > INT_MAX / multiplier)
612 if (total > INT_MAX - secs)
627 fmt_timeframe(time_t t)
630 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */
632 unsigned int sec, min, hrs, day;
633 unsigned long long week;
651 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs);
653 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min);
655 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec);
661 * Returns a standardized host+port identifier string.
662 * Caller must free returned string.
665 put_host_port(const char *host, u_short port)
669 if (port == 0 || port == SSH_DEFAULT_PORT)
670 return(xstrdup(host));
671 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1)
672 fatal("put_host_port: asprintf: %s", strerror(errno));
673 debug3("put_host_port: %s", hoststr);
678 * Search for next delimiter between hostnames/addresses and ports.
679 * Argument may be modified (for termination).
680 * Returns *cp if parsing succeeds.
681 * *cp is set to the start of the next field, if one was found.
682 * The delimiter char, if present, is stored in delim.
683 * If this is the last field, *cp is set to NULL.
686 hpdelim2(char **cp, char *delim)
690 if (cp == NULL || *cp == NULL)
695 if ((s = strchr(s, ']')) == NULL)
699 } else if ((s = strpbrk(s, ":/")) == NULL)
700 s = *cp + strlen(*cp); /* skip to end (see first case below) */
704 *cp = NULL; /* no more fields*/
711 *s = '\0'; /* terminate */
722 /* The common case: only accept colon as delimiter. */
726 char *r, delim = '\0';
728 r = hpdelim2(cp, &delim);
735 cleanhostname(char *host)
737 if (*host == '[' && host[strlen(host) - 1] == ']') {
738 host[strlen(host) - 1] = '\0';
749 if (*cp == ':') /* Leading colon is part of file name. */
755 if (*cp == '@' && *(cp+1) == '[')
757 if (*cp == ']' && *(cp+1) == ':' && flag)
759 if (*cp == ':' && !flag)
768 * Parse a [user@]host:[path] string.
769 * Caller must free returned user, host and path.
770 * Any of the pointer return arguments may be NULL (useful for syntax checking).
771 * If user was not specified then *userp will be set to NULL.
772 * If host was not specified then *hostp will be set to NULL.
773 * If path was not specified then *pathp will be set to ".".
774 * Returns 0 on success, -1 on failure.
777 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp)
779 char *user = NULL, *host = NULL, *path = NULL;
792 /* Check for remote syntax: [user@]host:[path] */
793 if ((tmp = colon(sdup)) == NULL)
796 /* Extract optional path */
802 /* Extract optional user and mandatory host */
803 tmp = strrchr(sdup, '@');
806 host = xstrdup(cleanhostname(tmp));
808 user = xstrdup(sdup);
810 host = xstrdup(cleanhostname(sdup));
837 * Parse a [user@]host[:port] string.
838 * Caller must free returned user and host.
839 * Any of the pointer return arguments may be NULL (useful for syntax checking).
840 * If user was not specified then *userp will be set to NULL.
841 * If port was not specified then *portp will be -1.
842 * Returns 0 on success, -1 on failure.
845 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
847 char *sdup, *cp, *tmp;
848 char *user = NULL, *host = NULL;
849 int port = -1, ret = -1;
858 if ((sdup = tmp = strdup(s)) == NULL)
860 /* Extract optional username */
861 if ((cp = strrchr(tmp, '@')) != NULL) {
865 if ((user = strdup(tmp)) == NULL)
869 /* Extract mandatory hostname */
870 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0')
872 host = xstrdup(cleanhostname(cp));
873 /* Convert and verify optional port */
874 if (tmp != NULL && *tmp != '\0') {
875 if ((port = a2port(tmp)) <= 0)
898 * Converts a two-byte hex string to decimal.
899 * Returns the decimal value or -1 for invalid input.
902 hexchar(const char *s)
904 unsigned char result[2];
907 for (i = 0; i < 2; i++) {
908 if (s[i] >= '0' && s[i] <= '9')
909 result[i] = (unsigned char)(s[i] - '0');
910 else if (s[i] >= 'a' && s[i] <= 'f')
911 result[i] = (unsigned char)(s[i] - 'a') + 10;
912 else if (s[i] >= 'A' && s[i] <= 'F')
913 result[i] = (unsigned char)(s[i] - 'A') + 10;
917 return (result[0] << 4) | result[1];
921 * Decode an url-encoded string.
922 * Returns a newly allocated string on success or NULL on failure.
925 urldecode(const char *src)
930 ret = xmalloc(strlen(src) + 1);
931 for (dst = ret; *src != '\0'; src++) {
937 if (!isxdigit((unsigned char)src[1]) ||
938 !isxdigit((unsigned char)src[2]) ||
939 (ch = hexchar(src + 1)) == -1) {
957 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI.
958 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04
959 * Either user or path may be url-encoded (but not host or port).
960 * Caller must free returned user, host and path.
961 * Any of the pointer return arguments may be NULL (useful for syntax checking)
962 * but the scheme must always be specified.
963 * If user was not specified then *userp will be set to NULL.
964 * If port was not specified then *portp will be -1.
965 * If path was not specified then *pathp will be set to NULL.
966 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri.
969 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp,
970 int *portp, char **pathp)
972 char *uridup, *cp, *tmp, ch;
973 char *user = NULL, *host = NULL, *path = NULL;
974 int port = -1, ret = -1;
977 len = strlen(scheme);
978 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0)
991 uridup = tmp = xstrdup(uri);
993 /* Extract optional ssh-info (username + connection params) */
994 if ((cp = strchr(tmp, '@')) != NULL) {
998 /* Extract username and connection params */
999 if ((delim = strchr(tmp, ';')) != NULL) {
1000 /* Just ignore connection params for now */
1004 /* Empty username */
1007 if ((user = urldecode(tmp)) == NULL)
1012 /* Extract mandatory hostname */
1013 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0')
1015 host = xstrdup(cleanhostname(cp));
1016 if (!valid_domain(host, 0, NULL))
1019 if (tmp != NULL && *tmp != '\0') {
1021 /* Convert and verify port. */
1022 if ((cp = strchr(tmp, '/')) != NULL)
1024 if ((port = a2port(tmp)) <= 0)
1026 tmp = cp ? cp + 1 : NULL;
1028 if (tmp != NULL && *tmp != '\0') {
1029 /* Extract optional path */
1030 if ((path = urldecode(tmp)) == NULL)
1036 if (userp != NULL) {
1040 if (hostp != NULL) {
1046 if (pathp != NULL) {
1059 /* function to assist building execv() arguments */
1061 addargs(arglist *args, char *fmt, ...)
1069 r = vasprintf(&cp, fmt, ap);
1072 fatal_f("argument too long");
1074 nalloc = args->nalloc;
1075 if (args->list == NULL) {
1078 } else if (args->num > (256 * 1024))
1079 fatal_f("too many arguments");
1080 else if (args->num >= args->nalloc)
1081 fatal_f("arglist corrupt");
1082 else if (args->num+2 >= nalloc)
1085 args->list = xrecallocarray(args->list, args->nalloc,
1086 nalloc, sizeof(char *));
1087 args->nalloc = nalloc;
1088 args->list[args->num++] = cp;
1089 args->list[args->num] = NULL;
1093 replacearg(arglist *args, u_int which, char *fmt, ...)
1100 r = vasprintf(&cp, fmt, ap);
1103 fatal_f("argument too long");
1104 if (args->list == NULL || args->num >= args->nalloc)
1105 fatal_f("arglist corrupt");
1107 if (which >= args->num)
1108 fatal_f("tried to replace invalid arg %d >= %d",
1110 free(args->list[which]);
1111 args->list[which] = cp;
1115 freeargs(arglist *args)
1121 if (args->list != NULL && args->num < args->nalloc) {
1122 for (i = 0; i < args->num; i++)
1123 free(args->list[i]);
1126 args->nalloc = args->num = 0;
1131 * Expands tildes in the file name. Returns data allocated by xmalloc.
1132 * Warning: this calls getpw*.
1135 tilde_expand(const char *filename, uid_t uid, char **retp)
1137 char *ocopy = NULL, *copy, *s = NULL;
1138 const char *path = NULL, *user = NULL;
1141 int ret = -1, r, slash;
1144 if (*filename != '~') {
1145 *retp = xstrdup(filename);
1148 ocopy = copy = xstrdup(filename + 1);
1150 if (*copy == '\0') /* ~ */
1152 else if (*copy == '/') {
1153 copy += strspn(copy, "/");
1155 path = NULL; /* ~/ */
1157 path = copy; /* ~/path */
1160 if ((path = strchr(copy, '/')) != NULL) {
1161 copy[path - copy] = '\0';
1163 path += strspn(path, "/");
1164 if (*path == '\0') /* ~user/ */
1166 /* else ~user/path */
1171 if ((pw = getpwnam(user)) == NULL) {
1172 error_f("No such user %s", user);
1175 } else if ((pw = getpwuid(uid)) == NULL) {
1176 error_f("No such uid %ld", (long)uid);
1180 /* Make sure directory has a trailing '/' */
1181 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/';
1183 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir,
1184 slash ? "/" : "", path != NULL ? path : "")) <= 0) {
1185 error_f("xasprintf failed");
1188 if (r >= PATH_MAX) {
1189 error_f("Path too long");
1203 tilde_expand_filename(const char *filename, uid_t uid)
1207 if (tilde_expand(filename, uid, &ret) != 0)
1213 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT}
1214 * substitutions. A number of escapes may be specified as
1215 * (char *escape_chars, char *replacement) pairs. The list must be terminated
1216 * by a NULL escape_char. Returns replaced string in memory allocated by
1217 * xmalloc which the caller must free.
1220 vdollar_percent_expand(int *parseerror, int dollar, int percent,
1221 const char *string, va_list ap)
1223 #define EXPAND_MAX_KEYS 16
1224 u_int num_keys = 0, i;
1228 } keys[EXPAND_MAX_KEYS];
1230 int r, missingvar = 0;
1231 char *ret = NULL, *var, *varend, *val;
1234 if ((buf = sshbuf_new()) == NULL)
1235 fatal_f("sshbuf_new failed");
1236 if (parseerror == NULL)
1237 fatal_f("null parseerror arg");
1240 /* Gather keys if we're doing percent expansion. */
1242 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) {
1243 keys[num_keys].key = va_arg(ap, char *);
1244 if (keys[num_keys].key == NULL)
1246 keys[num_keys].repl = va_arg(ap, char *);
1247 if (keys[num_keys].repl == NULL) {
1248 fatal_f("NULL replacement for token %s",
1249 keys[num_keys].key);
1252 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL)
1253 fatal_f("too many keys");
1255 fatal_f("percent expansion without token list");
1259 for (i = 0; *string != '\0'; string++) {
1260 /* Optionally process ${ENVIRONMENT} expansions. */
1261 if (dollar && string[0] == '$' && string[1] == '{') {
1262 string += 2; /* skip over '${' */
1263 if ((varend = strchr(string, '}')) == NULL) {
1264 error_f("environment variable '%s' missing "
1265 "closing '}'", string);
1268 len = varend - string;
1270 error_f("zero-length environment variable");
1273 var = xmalloc(len + 1);
1274 (void)strlcpy(var, string, len + 1);
1275 if ((val = getenv(var)) == NULL) {
1276 error_f("env var ${%s} has no value", var);
1279 debug3_f("expand ${%s} -> '%s'", var, val);
1280 if ((r = sshbuf_put(buf, val, strlen(val))) !=0)
1281 fatal_fr(r, "sshbuf_put ${}");
1289 * Process percent expansions if we have a list of TOKENs.
1290 * If we're not doing percent expansion everything just gets
1293 if (*string != '%' || !percent) {
1295 if ((r = sshbuf_put_u8(buf, *string)) != 0)
1296 fatal_fr(r, "sshbuf_put_u8 %%");
1303 if (*string == '\0') {
1304 error_f("invalid format");
1307 for (i = 0; i < num_keys; i++) {
1308 if (strchr(keys[i].key, *string) != NULL) {
1309 if ((r = sshbuf_put(buf, keys[i].repl,
1310 strlen(keys[i].repl))) != 0)
1311 fatal_fr(r, "sshbuf_put %%-repl");
1315 if (i >= num_keys) {
1316 error_f("unknown key %%%c", *string);
1320 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL)
1321 fatal_f("sshbuf_dup_string failed");
1325 return *parseerror ? NULL : ret;
1326 #undef EXPAND_MAX_KEYS
1330 * Expand only environment variables.
1331 * Note that although this function is variadic like the other similar
1332 * functions, any such arguments will be unused.
1336 dollar_expand(int *parseerr, const char *string, ...)
1342 va_start(ap, string);
1343 ret = vdollar_percent_expand(&err, 1, 0, string, ap);
1345 if (parseerr != NULL)
1351 * Returns expanded string or NULL if a specified environment variable is
1352 * not defined, or calls fatal if the string is invalid.
1355 percent_expand(const char *string, ...)
1361 va_start(ap, string);
1362 ret = vdollar_percent_expand(&err, 0, 1, string, ap);
1370 * Returns expanded string or NULL if a specified environment variable is
1371 * not defined, or calls fatal if the string is invalid.
1374 percent_dollar_expand(const char *string, ...)
1380 va_start(ap, string);
1381 ret = vdollar_percent_expand(&err, 1, 1, string, ap);
1389 tun_open(int tun, int mode, char **ifname)
1391 #if defined(CUSTOM_SYS_TUN_OPEN)
1392 return (sys_tun_open(tun, mode, ifname));
1393 #elif defined(SSH_TUN_OPENBSD)
1397 const char *tunbase = "tun";
1402 if (mode == SSH_TUNMODE_ETHERNET)
1405 /* Open the tunnel device */
1406 if (tun <= SSH_TUNID_MAX) {
1407 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
1408 fd = open(name, O_RDWR);
1409 } else if (tun == SSH_TUNID_ANY) {
1410 for (tun = 100; tun >= 0; tun--) {
1411 snprintf(name, sizeof(name), "/dev/%s%d",
1413 if ((fd = open(name, O_RDWR)) >= 0)
1417 debug_f("invalid tunnel %u", tun);
1422 debug_f("%s open: %s", name, strerror(errno));
1426 debug_f("%s mode %d fd %d", name, mode, fd);
1428 /* Bring interface up if it is not already */
1429 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
1430 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
1433 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) {
1434 debug_f("get interface %s flags: %s", ifr.ifr_name,
1439 if (!(ifr.ifr_flags & IFF_UP)) {
1440 ifr.ifr_flags |= IFF_UP;
1441 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) {
1442 debug_f("activate interface %s: %s", ifr.ifr_name,
1449 *ifname = xstrdup(ifr.ifr_name);
1461 error("Tunnel interfaces are not supported on this platform");
1467 sanitise_stdfd(void)
1471 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1472 fprintf(stderr, "Couldn't open /dev/null: %s\n",
1476 while (++dupfd <= STDERR_FILENO) {
1477 /* Only populate closed fds. */
1478 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) {
1479 if (dup2(nullfd, dupfd) == -1) {
1480 fprintf(stderr, "dup2: %s\n", strerror(errno));
1485 if (nullfd > STDERR_FILENO)
1490 tohex(const void *vp, size_t l)
1492 const u_char *p = (const u_char *)vp;
1497 return xstrdup("tohex: length > 65536");
1501 for (i = 0; i < l; i++) {
1502 snprintf(b, sizeof(b), "%02x", p[i]);
1509 * Extend string *sp by the specified format. If *sp is not NULL (or empty),
1510 * then the separator 'sep' will be prepended before the formatted arguments.
1511 * Extended strings are heap allocated.
1514 xextendf(char **sp, const char *sep, const char *fmt, ...)
1520 xvasprintf(&tmp1, fmt, ap);
1523 if (*sp == NULL || **sp == '\0') {
1528 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1);
1536 get_u64(const void *vp)
1538 const u_char *p = (const u_char *)vp;
1541 v = (u_int64_t)p[0] << 56;
1542 v |= (u_int64_t)p[1] << 48;
1543 v |= (u_int64_t)p[2] << 40;
1544 v |= (u_int64_t)p[3] << 32;
1545 v |= (u_int64_t)p[4] << 24;
1546 v |= (u_int64_t)p[5] << 16;
1547 v |= (u_int64_t)p[6] << 8;
1548 v |= (u_int64_t)p[7];
1554 get_u32(const void *vp)
1556 const u_char *p = (const u_char *)vp;
1559 v = (u_int32_t)p[0] << 24;
1560 v |= (u_int32_t)p[1] << 16;
1561 v |= (u_int32_t)p[2] << 8;
1562 v |= (u_int32_t)p[3];
1568 get_u32_le(const void *vp)
1570 const u_char *p = (const u_char *)vp;
1573 v = (u_int32_t)p[0];
1574 v |= (u_int32_t)p[1] << 8;
1575 v |= (u_int32_t)p[2] << 16;
1576 v |= (u_int32_t)p[3] << 24;
1582 get_u16(const void *vp)
1584 const u_char *p = (const u_char *)vp;
1587 v = (u_int16_t)p[0] << 8;
1588 v |= (u_int16_t)p[1];
1594 put_u64(void *vp, u_int64_t v)
1596 u_char *p = (u_char *)vp;
1598 p[0] = (u_char)(v >> 56) & 0xff;
1599 p[1] = (u_char)(v >> 48) & 0xff;
1600 p[2] = (u_char)(v >> 40) & 0xff;
1601 p[3] = (u_char)(v >> 32) & 0xff;
1602 p[4] = (u_char)(v >> 24) & 0xff;
1603 p[5] = (u_char)(v >> 16) & 0xff;
1604 p[6] = (u_char)(v >> 8) & 0xff;
1605 p[7] = (u_char)v & 0xff;
1609 put_u32(void *vp, u_int32_t v)
1611 u_char *p = (u_char *)vp;
1613 p[0] = (u_char)(v >> 24) & 0xff;
1614 p[1] = (u_char)(v >> 16) & 0xff;
1615 p[2] = (u_char)(v >> 8) & 0xff;
1616 p[3] = (u_char)v & 0xff;
1620 put_u32_le(void *vp, u_int32_t v)
1622 u_char *p = (u_char *)vp;
1624 p[0] = (u_char)v & 0xff;
1625 p[1] = (u_char)(v >> 8) & 0xff;
1626 p[2] = (u_char)(v >> 16) & 0xff;
1627 p[3] = (u_char)(v >> 24) & 0xff;
1631 put_u16(void *vp, u_int16_t v)
1633 u_char *p = (u_char *)vp;
1635 p[0] = (u_char)(v >> 8) & 0xff;
1636 p[1] = (u_char)v & 0xff;
1640 ms_subtract_diff(struct timeval *start, int *ms)
1642 struct timeval diff, finish;
1644 monotime_tv(&finish);
1645 timersub(&finish, start, &diff);
1646 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
1650 ms_to_timespec(struct timespec *ts, int ms)
1654 ts->tv_sec = ms / 1000;
1655 ts->tv_nsec = (ms % 1000) * 1000 * 1000;
1659 monotime_ts(struct timespec *ts)
1662 #if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \
1663 defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME))
1664 static int gettime_failed = 0;
1666 if (!gettime_failed) {
1667 # ifdef CLOCK_BOOTTIME
1668 if (clock_gettime(CLOCK_BOOTTIME, ts) == 0)
1670 # endif /* CLOCK_BOOTTIME */
1671 # ifdef CLOCK_MONOTONIC
1672 if (clock_gettime(CLOCK_MONOTONIC, ts) == 0)
1674 # endif /* CLOCK_MONOTONIC */
1675 # ifdef CLOCK_REALTIME
1676 /* Not monotonic, but we're almost out of options here. */
1677 if (clock_gettime(CLOCK_REALTIME, ts) == 0)
1679 # endif /* CLOCK_REALTIME */
1680 debug3("clock_gettime: %s", strerror(errno));
1683 #endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */
1684 gettimeofday(&tv, NULL);
1685 ts->tv_sec = tv.tv_sec;
1686 ts->tv_nsec = (long)tv.tv_usec * 1000;
1690 monotime_tv(struct timeval *tv)
1695 tv->tv_sec = ts.tv_sec;
1696 tv->tv_usec = ts.tv_nsec / 1000;
1709 monotime_double(void)
1714 return ts.tv_sec + ((double)ts.tv_nsec / 1000000000);
1718 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen)
1720 bw->buflen = buflen;
1722 bw->thresh = buflen;
1724 timerclear(&bw->bwstart);
1725 timerclear(&bw->bwend);
1728 /* Callback from read/write loop to insert bandwidth-limiting delays */
1730 bandwidth_limit(struct bwlimit *bw, size_t read_len)
1733 struct timespec ts, rm;
1735 bw->lamt += read_len;
1736 if (!timerisset(&bw->bwstart)) {
1737 monotime_tv(&bw->bwstart);
1740 if (bw->lamt < bw->thresh)
1743 monotime_tv(&bw->bwend);
1744 timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
1745 if (!timerisset(&bw->bwend))
1749 waitlen = (double)1000000L * bw->lamt / bw->rate;
1751 bw->bwstart.tv_sec = waitlen / 1000000L;
1752 bw->bwstart.tv_usec = waitlen % 1000000L;
1754 if (timercmp(&bw->bwstart, &bw->bwend, >)) {
1755 timersub(&bw->bwstart, &bw->bwend, &bw->bwend);
1757 /* Adjust the wait time */
1758 if (bw->bwend.tv_sec) {
1760 if (bw->thresh < bw->buflen / 4)
1761 bw->thresh = bw->buflen / 4;
1762 } else if (bw->bwend.tv_usec < 10000) {
1764 if (bw->thresh > bw->buflen * 8)
1765 bw->thresh = bw->buflen * 8;
1768 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts);
1769 while (nanosleep(&ts, &rm) == -1) {
1777 monotime_tv(&bw->bwstart);
1780 /* Make a template filename for mk[sd]temp() */
1782 mktemp_proto(char *s, size_t len)
1787 if ((tmpdir = getenv("TMPDIR")) != NULL) {
1788 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir);
1789 if (r > 0 && (size_t)r < len)
1792 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX");
1793 if (r < 0 || (size_t)r >= len)
1794 fatal_f("template string too short");
1797 static const struct {
1801 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */
1802 { "af11", IPTOS_DSCP_AF11 },
1803 { "af12", IPTOS_DSCP_AF12 },
1804 { "af13", IPTOS_DSCP_AF13 },
1805 { "af21", IPTOS_DSCP_AF21 },
1806 { "af22", IPTOS_DSCP_AF22 },
1807 { "af23", IPTOS_DSCP_AF23 },
1808 { "af31", IPTOS_DSCP_AF31 },
1809 { "af32", IPTOS_DSCP_AF32 },
1810 { "af33", IPTOS_DSCP_AF33 },
1811 { "af41", IPTOS_DSCP_AF41 },
1812 { "af42", IPTOS_DSCP_AF42 },
1813 { "af43", IPTOS_DSCP_AF43 },
1814 { "cs0", IPTOS_DSCP_CS0 },
1815 { "cs1", IPTOS_DSCP_CS1 },
1816 { "cs2", IPTOS_DSCP_CS2 },
1817 { "cs3", IPTOS_DSCP_CS3 },
1818 { "cs4", IPTOS_DSCP_CS4 },
1819 { "cs5", IPTOS_DSCP_CS5 },
1820 { "cs6", IPTOS_DSCP_CS6 },
1821 { "cs7", IPTOS_DSCP_CS7 },
1822 { "ef", IPTOS_DSCP_EF },
1823 { "le", IPTOS_DSCP_LE },
1824 { "lowdelay", IPTOS_LOWDELAY },
1825 { "throughput", IPTOS_THROUGHPUT },
1826 { "reliability", IPTOS_RELIABILITY },
1831 parse_ipqos(const char *cp)
1839 for (i = 0; ipqos[i].name != NULL; i++) {
1840 if (strcasecmp(cp, ipqos[i].name) == 0)
1841 return ipqos[i].value;
1843 /* Try parsing as an integer */
1844 val = strtol(cp, &ep, 0);
1845 if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255)
1851 iptos2str(int iptos)
1854 static char iptos_str[sizeof "0xff"];
1856 for (i = 0; ipqos[i].name != NULL; i++) {
1857 if (ipqos[i].value == iptos)
1858 return ipqos[i].name;
1860 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos);
1868 *s = tolower((u_char)*s);
1872 unix_listener(const char *path, int backlog, int unlink_first)
1874 struct sockaddr_un sunaddr;
1875 int saved_errno, sock;
1877 memset(&sunaddr, 0, sizeof(sunaddr));
1878 sunaddr.sun_family = AF_UNIX;
1879 if (strlcpy(sunaddr.sun_path, path,
1880 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
1881 error_f("path \"%s\" too long for Unix domain socket", path);
1882 errno = ENAMETOOLONG;
1886 sock = socket(PF_UNIX, SOCK_STREAM, 0);
1888 saved_errno = errno;
1889 error_f("socket: %.100s", strerror(errno));
1890 errno = saved_errno;
1893 if (unlink_first == 1) {
1894 if (unlink(path) != 0 && errno != ENOENT)
1895 error("unlink(%s): %.100s", path, strerror(errno));
1897 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
1898 saved_errno = errno;
1899 error_f("cannot bind to path %s: %s", path, strerror(errno));
1901 errno = saved_errno;
1904 if (listen(sock, backlog) == -1) {
1905 saved_errno = errno;
1906 error_f("cannot listen on path %s: %s", path, strerror(errno));
1909 errno = saved_errno;
1916 sock_set_v6only(int s)
1918 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
1921 debug3("%s: set socket %d IPV6_V6ONLY", __func__, s);
1922 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1)
1923 error("setsockopt IPV6_V6ONLY: %s", strerror(errno));
1928 * Compares two strings that maybe be NULL. Returns non-zero if strings
1929 * are both NULL or are identical, returns zero otherwise.
1932 strcmp_maybe_null(const char *a, const char *b)
1934 if ((a == NULL && b != NULL) || (a != NULL && b == NULL))
1936 if (a != NULL && strcmp(a, b) != 0)
1942 * Compare two forwards, returning non-zero if they are identical or
1946 forward_equals(const struct Forward *a, const struct Forward *b)
1948 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0)
1950 if (a->listen_port != b->listen_port)
1952 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0)
1954 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0)
1956 if (a->connect_port != b->connect_port)
1958 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0)
1960 /* allocated_port and handle are not checked */
1964 /* returns 1 if process is already daemonized, 0 otherwise */
1970 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
1972 return 0; /* have controlling terminal */
1975 return 0; /* parent is not init */
1976 if (getsid(0) != getpid())
1977 return 0; /* not session leader */
1978 debug3("already daemonized");
1983 * Splits 's' into an argument vector. Handles quoted string and basic
1984 * escape characters (\\, \", \'). Caller must free the argument vector
1988 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment)
1990 int r = SSH_ERR_INTERNAL_ERROR;
1991 int argc = 0, quote, i, j;
1992 char *arg, **argv = xcalloc(1, sizeof(*argv));
1997 for (i = 0; s[i] != '\0'; i++) {
1998 /* Skip leading whitespace */
1999 if (s[i] == ' ' || s[i] == '\t')
2001 if (terminate_on_comment && s[i] == '#')
2003 /* Start of a token */
2006 argv = xreallocarray(argv, (argc + 2), sizeof(*argv));
2007 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1);
2010 /* Copy the token in, removing escapes */
2011 for (j = 0; s[i] != '\0'; i++) {
2013 if (s[i + 1] == '\'' ||
2016 (quote == 0 && s[i + 1] == ' ')) {
2020 /* Unrecognised escape */
2023 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t'))
2025 else if (quote == 0 && (s[i] == '\"' || s[i] == '\''))
2026 quote = s[i]; /* quote start */
2027 else if (quote != 0 && s[i] == quote)
2028 quote = 0; /* quote end */
2034 /* Ran out of string looking for close quote */
2035 r = SSH_ERR_INVALID_FORMAT;
2048 if (argc != 0 && argv != NULL) {
2049 for (i = 0; i < argc; i++)
2057 * Reassemble an argument vector into a string, quoting and escaping as
2058 * necessary. Caller must free returned string.
2061 argv_assemble(int argc, char **argv)
2065 struct sshbuf *buf, *arg;
2067 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL)
2068 fatal_f("sshbuf_new failed");
2070 for (i = 0; i < argc; i++) {
2073 for (j = 0; argv[i][j] != '\0'; j++) {
2080 r = sshbuf_put_u8(arg, c);
2085 if ((r = sshbuf_put_u8(arg, '\\')) != 0)
2089 r = sshbuf_put_u8(arg, c);
2093 fatal_fr(r, "sshbuf_put_u8");
2095 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) ||
2096 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) ||
2097 (r = sshbuf_putb(buf, arg)) != 0 ||
2098 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0))
2099 fatal_fr(r, "assemble");
2101 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL)
2102 fatal_f("malloc failed");
2103 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf));
2104 ret[sshbuf_len(buf)] = '\0';
2111 argv_next(int *argcp, char ***argvp)
2113 char *ret = (*argvp)[0];
2115 if (*argcp > 0 && ret != NULL) {
2123 argv_consume(int *argcp)
2129 argv_free(char **av, int ac)
2135 for (i = 0; i < ac; i++)
2140 /* Returns 0 if pid exited cleanly, non-zero otherwise */
2142 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)
2146 while (waitpid(pid, &status, 0) == -1) {
2147 if (errno != EINTR) {
2148 error("%s waitpid: %s", tag, strerror(errno));
2152 if (WIFSIGNALED(status)) {
2153 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status));
2155 } else if (WEXITSTATUS(status) != 0) {
2156 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO,
2157 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status));
2164 * Check a given path for security. This is defined as all components
2165 * of the path to the file must be owned by either the owner of
2166 * of the file or root and no directories must be group or world writable.
2168 * XXX Should any specific check be done for sym links ?
2170 * Takes a file name, its stat information (preferably from fstat() to
2171 * avoid races), the uid of the expected owner, their home directory and an
2172 * error buffer plus max size as arguments.
2174 * Returns 0 on success and -1 on failure
2177 safe_path(const char *name, struct stat *stp, const char *pw_dir,
2178 uid_t uid, char *err, size_t errlen)
2180 char buf[PATH_MAX], homedir[PATH_MAX];
2182 int comparehome = 0;
2185 if (realpath(name, buf) == NULL) {
2186 snprintf(err, errlen, "realpath %s failed: %s", name,
2190 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL)
2193 if (!S_ISREG(stp->st_mode)) {
2194 snprintf(err, errlen, "%s is not a regular file", buf);
2197 if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) ||
2198 (stp->st_mode & 022) != 0) {
2199 snprintf(err, errlen, "bad ownership or modes for file %s",
2204 /* for each component of the canonical path, walking upwards */
2206 if ((cp = dirname(buf)) == NULL) {
2207 snprintf(err, errlen, "dirname() failed");
2210 strlcpy(buf, cp, sizeof(buf));
2212 if (stat(buf, &st) == -1 ||
2213 (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) ||
2214 (st.st_mode & 022) != 0) {
2215 snprintf(err, errlen,
2216 "bad ownership or modes for directory %s", buf);
2220 /* If are past the homedir then we can stop */
2221 if (comparehome && strcmp(homedir, buf) == 0)
2225 * dirname should always complete with a "/" path,
2226 * but we can be paranoid and check for "." too
2228 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0))
2235 * Version of safe_path() that accepts an open file descriptor to
2238 * Returns 0 on success and -1 on failure
2241 safe_path_fd(int fd, const char *file, struct passwd *pw,
2242 char *err, size_t errlen)
2246 /* check the open file to avoid races */
2247 if (fstat(fd, &st) == -1) {
2248 snprintf(err, errlen, "cannot stat file %s: %s",
2249 file, strerror(errno));
2252 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen);
2256 * Sets the value of the given variable in the environment. If the variable
2257 * already exists, its value is overridden.
2260 child_set_env(char ***envp, u_int *envsizep, const char *name,
2267 if (strchr(name, '=') != NULL) {
2268 error("Invalid environment variable \"%.100s\"", name);
2273 * If we're passed an uninitialized list, allocate a single null
2274 * entry before continuing.
2276 if (*envp == NULL && *envsizep == 0) {
2277 *envp = xmalloc(sizeof(char *));
2283 * Find the slot where the value should be stored. If the variable
2284 * already exists, we reuse the slot; otherwise we append a new slot
2285 * at the end of the array, expanding if necessary.
2288 namelen = strlen(name);
2289 for (i = 0; env[i]; i++)
2290 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
2293 /* Reuse the slot. */
2296 /* New variable. Expand if necessary. */
2297 envsize = *envsizep;
2298 if (i >= envsize - 1) {
2299 if (envsize >= 1000)
2300 fatal("child_set_env: too many env vars");
2302 env = (*envp) = xreallocarray(env, envsize, sizeof(char *));
2303 *envsizep = envsize;
2305 /* Need to set the NULL pointer at end of array beyond the new slot. */
2309 /* Allocate space and format the variable in the appropriate slot. */
2311 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
2312 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
2316 * Check and optionally lowercase a domain name, also removes trailing '.'
2317 * Returns 1 on success and 0 on failure, storing an error message in errstr.
2320 valid_domain(char *name, int makelower, const char **errstr)
2322 size_t i, l = strlen(name);
2323 u_char c, last = '\0';
2324 static char errbuf[256];
2327 strlcpy(errbuf, "empty domain name", sizeof(errbuf));
2330 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) {
2331 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" "
2332 "starts with invalid character", name);
2335 for (i = 0; i < l; i++) {
2336 c = tolower((u_char)name[i]);
2339 if (last == '.' && c == '.') {
2340 snprintf(errbuf, sizeof(errbuf), "domain name "
2341 "\"%.100s\" contains consecutive separators", name);
2344 if (c != '.' && c != '-' && !isalnum(c) &&
2345 c != '_') /* technically invalid, but common */ {
2346 snprintf(errbuf, sizeof(errbuf), "domain name "
2347 "\"%.100s\" contains invalid characters", name);
2352 if (name[l - 1] == '.')
2364 * Verify that a environment variable name (not including initial '$') is
2365 * valid; consisting of one or more alphanumeric or underscore characters only.
2366 * Returns 1 on valid, 0 otherwise.
2369 valid_env_name(const char *name)
2373 if (name[0] == '\0')
2375 for (cp = name; *cp != '\0'; cp++) {
2376 if (!isalnum((u_char)*cp) && *cp != '_')
2383 atoi_err(const char *nptr, int *val)
2385 const char *errstr = NULL;
2388 if (nptr == NULL || *nptr == '\0')
2390 num = strtonum(nptr, 0, INT_MAX, &errstr);
2397 parse_absolute_time(const char *s, uint64_t *tp)
2409 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) {
2412 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) {
2417 * POSIX strptime says "The application shall ensure that there
2418 * is white-space or other non-alphanumeric characters between
2419 * any two conversion specifications" so arrange things this way.
2422 case 8: /* YYYYMMDD */
2424 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
2426 case 12: /* YYYYMMDDHHMM */
2427 fmt = "%Y-%m-%dT%H:%M";
2428 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s",
2429 s, s + 4, s + 6, s + 8, s + 10);
2431 case 14: /* YYYYMMDDHHMMSS */
2432 fmt = "%Y-%m-%dT%H:%M:%S";
2433 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
2434 s, s + 4, s + 6, s + 8, s + 10, s + 12);
2437 return SSH_ERR_INVALID_FORMAT;
2440 memset(&tm, 0, sizeof(tm));
2441 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0')
2442 return SSH_ERR_INVALID_FORMAT;
2444 if ((tt = timegm(&tm)) < 0)
2445 return SSH_ERR_INVALID_FORMAT;
2447 if ((tt = mktime(&tm)) < 0)
2448 return SSH_ERR_INVALID_FORMAT;
2456 format_absolute_time(uint64_t t, char *buf, size_t len)
2458 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t;
2461 localtime_r(&tt, &tm);
2462 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
2465 /* check if path is absolute */
2467 path_absolute(const char *path)
2469 return (*path == '/') ? 1 : 0;
2473 skip_space(char **cpp)
2477 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++)
2482 /* authorized_key-style options parsing helpers */
2485 * Match flag 'opt' in *optsp, and if allow_negate is set then also match
2486 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0
2487 * if negated option matches.
2488 * If the option or negated option matches, then *optsp is updated to
2489 * point to the first character after the option.
2492 opt_flag(const char *opt, int allow_negate, const char **optsp)
2494 size_t opt_len = strlen(opt);
2495 const char *opts = *optsp;
2498 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) {
2502 if (strncasecmp(opts, opt, opt_len) == 0) {
2503 *optsp = opts + opt_len;
2504 return negate ? 0 : 1;
2510 opt_dequote(const char **sp, const char **errstrp)
2512 const char *s = *sp;
2518 *errstrp = "missing start quote";
2522 if ((ret = malloc(strlen((s)) + 1)) == NULL) {
2523 *errstrp = "memory allocation failed";
2526 for (i = 0; *s != '\0' && *s != '"';) {
2527 if (s[0] == '\\' && s[1] == '"')
2532 *errstrp = "missing end quote";
2543 opt_match(const char **opts, const char *term)
2545 if (strncasecmp((*opts), term, strlen(term)) == 0 &&
2546 (*opts)[strlen(term)] == '=') {
2547 *opts += strlen(term) + 1;
2554 opt_array_append2(const char *file, const int line, const char *directive,
2555 char ***array, int **iarray, u_int *lp, const char *s, int i)
2559 fatal("%s line %d: Too many %s entries", file, line, directive);
2561 if (iarray != NULL) {
2562 *iarray = xrecallocarray(*iarray, *lp, *lp + 1,
2567 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array));
2568 (*array)[*lp] = xstrdup(s);
2573 opt_array_append(const char *file, const int line, const char *directive,
2574 char ***array, u_int *lp, const char *s)
2576 opt_array_append2(file, line, directive, array, NULL, lp, s, 0);
2580 ssh_signal(int signum, sshsig_t handler)
2582 struct sigaction sa, osa;
2584 /* mask all other signals while in handler */
2585 memset(&sa, 0, sizeof(sa));
2586 sa.sa_handler = handler;
2587 sigfillset(&sa.sa_mask);
2588 #if defined(SA_RESTART) && !defined(NO_SA_RESTART)
2589 if (signum != SIGALRM)
2590 sa.sa_flags = SA_RESTART;
2592 if (sigaction(signum, &sa, &osa) == -1) {
2593 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno));
2596 return osa.sa_handler;
2600 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr)
2602 int devnull, ret = 0;
2604 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
2605 error_f("open %s: %s", _PATH_DEVNULL,
2609 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) ||
2610 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) ||
2611 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) {
2612 error_f("dup2: %s", strerror(errno));
2615 if (devnull > STDERR_FILENO)
2621 * Runs command in a subprocess with a minimal environment.
2622 * Returns pid on success, 0 on failure.
2623 * The child stdout and stderr maybe captured, left attached or sent to
2624 * /dev/null depending on the contents of flags.
2625 * "tag" is prepended to log messages.
2626 * NB. "command" is only used for logging; the actual command executed is
2630 subprocess(const char *tag, const char *command,
2631 int ac, char **av, FILE **child, u_int flags,
2632 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs)
2636 int fd, devnull, p[2], i;
2638 char *cp, errmsg[512];
2642 /* If dropping privs, then must specify user and restore function */
2643 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) {
2644 error("%s: inconsistent arguments", tag); /* XXX fatal? */
2647 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) {
2648 error("%s: no user for current uid", tag);
2654 debug3_f("%s command \"%s\" running as %s (flags 0x%x)",
2655 tag, command, pw->pw_name, flags);
2657 /* Check consistency */
2658 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
2659 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) {
2660 error_f("inconsistent flags");
2663 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) {
2664 error_f("inconsistent flags/output");
2669 * If executing an explicit binary, then verify the it exists
2670 * and appears safe-ish to execute
2672 if (!path_absolute(av[0])) {
2673 error("%s path is not absolute", tag);
2676 if (drop_privs != NULL)
2678 if (stat(av[0], &st) == -1) {
2679 error("Could not stat %s \"%s\": %s", tag,
2680 av[0], strerror(errno));
2681 goto restore_return;
2683 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 &&
2684 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) {
2685 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg);
2686 goto restore_return;
2688 /* Prepare to keep the child's stdout if requested */
2689 if (pipe(p) == -1) {
2690 error("%s: pipe: %s", tag, strerror(errno));
2692 if (restore_privs != NULL)
2696 if (restore_privs != NULL)
2699 switch ((pid = fork())) {
2700 case -1: /* error */
2701 error("%s: fork: %s", tag, strerror(errno));
2706 /* Prepare a minimal environment for the child. */
2707 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) {
2709 env = xcalloc(sizeof(*env), nenv);
2710 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH);
2711 child_set_env(&env, &nenv, "USER", pw->pw_name);
2712 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name);
2713 child_set_env(&env, &nenv, "HOME", pw->pw_dir);
2714 if ((cp = getenv("LANG")) != NULL)
2715 child_set_env(&env, &nenv, "LANG", cp);
2718 for (i = 1; i < NSIG; i++)
2719 ssh_signal(i, SIG_DFL);
2721 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
2722 error("%s: open %s: %s", tag, _PATH_DEVNULL,
2726 if (dup2(devnull, STDIN_FILENO) == -1) {
2727 error("%s: dup2: %s", tag, strerror(errno));
2731 /* Set up stdout as requested; leave stderr in place for now. */
2733 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0)
2735 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0)
2737 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) {
2738 error("%s: dup2: %s", tag, strerror(errno));
2741 closefrom(STDERR_FILENO + 1);
2743 if (geteuid() == 0 &&
2744 initgroups(pw->pw_name, pw->pw_gid) == -1) {
2745 error("%s: initgroups(%s, %u): %s", tag,
2746 pw->pw_name, (u_int)pw->pw_gid, strerror(errno));
2749 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) {
2750 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
2754 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) {
2755 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid,
2759 /* stdin is pointed to /dev/null at this point */
2760 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
2761 dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
2762 error("%s: dup2: %s", tag, strerror(errno));
2766 execve(av[0], av, env);
2769 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve",
2770 command, strerror(errno));
2772 default: /* parent */
2777 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0)
2779 else if ((f = fdopen(p[0], "r")) == NULL) {
2780 error("%s: fdopen: %s", tag, strerror(errno));
2782 /* Don't leave zombie child */
2784 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
2789 debug3_f("%s pid %ld", tag, (long)pid);
2796 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs)
2800 envlen = strlen(env);
2801 for (i = 0; i < nenvs; i++) {
2802 if (strncmp(envs[i], env, envlen) == 0 &&
2803 envs[i][envlen] == '=') {
2804 return envs[i] + envlen + 1;
2811 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs)
2816 name = xstrdup(env);
2817 if ((cp = strchr(name, '=')) == NULL) {
2819 return NULL; /* not env=val */
2822 ret = lookup_env_in_list(name, envs, nenvs);
2828 * Helpers for managing poll(2)/ppoll(2) timeouts
2829 * Will remember the earliest deadline and return it for use in poll/ppoll.
2832 /* Initialise a poll/ppoll timeout with an indefinite deadline */
2834 ptimeout_init(struct timespec *pt)
2837 * Deliberately invalid for ppoll(2).
2838 * Will be converted to NULL in ptimeout_get_tspec() later.
2844 /* Specify a poll/ppoll deadline of at most 'sec' seconds */
2846 ptimeout_deadline_sec(struct timespec *pt, long sec)
2848 if (pt->tv_sec == -1 || pt->tv_sec >= sec) {
2854 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */
2856 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p)
2858 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=))
2862 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */
2864 ptimeout_deadline_ms(struct timespec *pt, long ms)
2868 p.tv_sec = ms / 1000;
2869 p.tv_nsec = (ms % 1000) * 1000000;
2870 ptimeout_deadline_tsp(pt, &p);
2873 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */
2875 ptimeout_deadline_monotime(struct timespec *pt, time_t when)
2877 struct timespec now, t;
2883 if (timespeccmp(&now, &t, >=))
2884 ptimeout_deadline_sec(pt, 0);
2886 timespecsub(&t, &now, &t);
2887 ptimeout_deadline_tsp(pt, &t);
2891 /* Get a poll(2) timeout value in milliseconds */
2893 ptimeout_get_ms(struct timespec *pt)
2895 if (pt->tv_sec == -1)
2897 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000)
2899 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000);
2902 /* Get a ppoll(2) timeout value as a timespec pointer */
2904 ptimeout_get_tsp(struct timespec *pt)
2906 return pt->tv_sec == -1 ? NULL : pt;
2909 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */
2911 ptimeout_isset(struct timespec *pt)
2913 return pt->tv_sec != -1;