1 files changed, 491 insertions, 205 deletions

diff --git a/misc.c b/misc.c
index 40aeeef36..75c4113f0 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.113 2017/08/18 05:48:04 djm Exp $ */
+/* $OpenBSD: misc.c,v 1.127 2018/03/12 00:52:01 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -168,6 +168,73 @@ set_nodelay(int fd)
                 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
 }
 
+/* Allow local port reuse in TIME_WAIT */
+int
+set_reuseaddr(int fd)
+{
+        int on = 1;
+
+        if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
+                error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
+                return -1;
+        }
+        return 0;
+}
+
+/* Get/set routing domain */
+char *
+get_rdomain(int fd)
+{
+#if defined(HAVE_SYS_GET_RDOMAIN)
+        return sys_get_rdomain(fd);
+#elif defined(__OpenBSD__)
+        int rtable;
+        char *ret;
+        socklen_t len = sizeof(rtable);
+
+        if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) {
+                error("Failed to get routing domain for fd %d: %s",
+                    fd, strerror(errno));
+                return NULL;
+        }
+        xasprintf(&ret, "%d", rtable);
+        return ret;
+#else /* defined(__OpenBSD__) */
+        return NULL;
+#endif
+}
+
+int
+set_rdomain(int fd, const char *name)
+{
+#if defined(HAVE_SYS_SET_RDOMAIN)
+        return sys_set_rdomain(fd, name);
+#elif defined(__OpenBSD__)
+        int rtable;
+        const char *errstr;
+
+        if (name == NULL)
+                return 0; /* default table */
+
+        rtable = (int)strtonum(name, 0, 255, &errstr);
+        if (errstr != NULL) {
+                /* Shouldn't happen */
+                error("Invalid routing domain \"%s\": %s", name, errstr);
+                return -1;
+        }
+        if (setsockopt(fd, SOL_SOCKET, SO_RTABLE,
+            &rtable, sizeof(rtable)) == -1) {
+                error("Failed to set routing domain %d on fd %d: %s",
+                    rtable, fd, strerror(errno));
+                return -1;
+        }
+        return 0;
+#else /* defined(__OpenBSD__) */
+        error("Setting routing domain is not supported on this platform");
+        return -1;
+#endif
+}
+
 /* Characters considered whitespace in strsep calls. */
 #define WHITESPACE " \t\r\n"
 #define QUOTE   "\""
@@ -396,11 +463,12 @@ put_host_port(const char *host, u_short port)
  * Search for next delimiter between hostnames/addresses and ports.
  * Argument may be modified (for termination).
  * Returns *cp if parsing succeeds.
- * *cp is set to the start of the next delimiter, if one was found.
+ * *cp is set to the start of the next field, if one was found.
+ * The delimiter char, if present, is stored in delim.
  * If this is the last field, *cp is set to NULL.
  */
-char *
-hpdelim(char **cp)
+static char *
+hpdelim2(char **cp, char *delim)
 {
         char *s, *old;
 
@@ -423,6 +491,8 @@ hpdelim(char **cp)
 
         case ':':
         case '/':
+                if (delim != NULL)
+                        *delim = *s;
                 *s = '\0';      /* terminate */
                 *cp = s + 1;
                 break;
@@ -435,6 +505,12 @@ hpdelim(char **cp)
 }
 
 char *
+hpdelim(char **cp)
+{
+        return hpdelim2(cp, NULL);
+}
+
+char *
 cleanhostname(char *host)
 {
         if (*host == '[' && host[strlen(host) - 1] == ']') {
@@ -468,6 +544,75 @@ colon(char *cp)
 }
 
 /*
+ * Parse a [user@]host:[path] string.
+ * Caller must free returned user, host and path.
+ * Any of the pointer return arguments may be NULL (useful for syntax checking).
+ * If user was not specified then *userp will be set to NULL.
+ * If host was not specified then *hostp will be set to NULL.
+ * If path was not specified then *pathp will be set to ".".
+ * Returns 0 on success, -1 on failure.
+ */
+int
+parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp)
+{
+        char *user = NULL, *host = NULL, *path = NULL;
+        char *sdup, *tmp;
+        int ret = -1;
+
+        if (userp != NULL)
+                *userp = NULL;
+        if (hostp != NULL)
+                *hostp = NULL;
+        if (pathp != NULL)
+                *pathp = NULL;
+
+        sdup = xstrdup(s);
+
+        /* Check for remote syntax: [user@]host:[path] */
+        if ((tmp = colon(sdup)) == NULL)
+                goto out;
+
+        /* Extract optional path */
+        *tmp++ = '\0';
+        if (*tmp == '\0')
+                tmp = ".";
+        path = xstrdup(tmp);
+
+        /* Extract optional user and mandatory host */
+        tmp = strrchr(sdup, '@');
+        if (tmp != NULL) {
+                *tmp++ = '\0';
+                host = xstrdup(cleanhostname(tmp));
+                if (*sdup != '\0')
+                        user = xstrdup(sdup);
+        } else {
+                host = xstrdup(cleanhostname(sdup));
+                user = NULL;
+        }
+
+        /* Success */
+        if (userp != NULL) {
+                *userp = user;
+                user = NULL;
+        }
+        if (hostp != NULL) {
+                *hostp = host;
+                host = NULL;
+        }
+        if (pathp != NULL) {
+                *pathp = path;
+                path = NULL;
+        }
+        ret = 0;
+out:
+        free(sdup);
+        free(user);
+        free(host);
+        free(path);
+        return ret;
+}
+
+/*
  * Parse a [user@]host[:port] string.
  * Caller must free returned user and host.
  * Any of the pointer return arguments may be NULL (useful for syntax checking).
@@ -492,7 +637,7 @@ parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
         if ((sdup = tmp = strdup(s)) == NULL)
                 return -1;
         /* Extract optional username */
-        if ((cp = strchr(tmp, '@')) != NULL) {
+        if ((cp = strrchr(tmp, '@')) != NULL) {
                 *cp = '\0';
                 if (*tmp == '\0')
                         goto out;
@@ -528,6 +673,168 @@ parse_user_host_port(const char *s, char **userp, char **hostp, int *portp)
         return ret;
 }
 
+/*
+ * Converts a two-byte hex string to decimal.
+ * Returns the decimal value or -1 for invalid input.
+ */
+static int
+hexchar(const char *s)
+{
+        unsigned char result[2];
+        int i;
+
+        for (i = 0; i < 2; i++) {
+                if (s[i] >= '0' && s[i] <= '9')
+                        result[i] = (unsigned char)(s[i] - '0');
+                else if (s[i] >= 'a' && s[i] <= 'f')
+                        result[i] = (unsigned char)(s[i] - 'a') + 10;
+                else if (s[i] >= 'A' && s[i] <= 'F')
+                        result[i] = (unsigned char)(s[i] - 'A') + 10;
+                else
+                        return -1;
+        }
+        return (result[0] << 4) | result[1];
+}
+
+/*
+ * Decode an url-encoded string.
+ * Returns a newly allocated string on success or NULL on failure.
+ */
+static char *
+urldecode(const char *src)
+{
+        char *ret, *dst;
+        int ch;
+
+        ret = xmalloc(strlen(src) + 1);
+        for (dst = ret; *src != '\0'; src++) {
+                switch (*src) {
+                case '+':
+                        *dst++ = ' ';
+                        break;
+                case '%':
+                        if (!isxdigit((unsigned char)src[1]) ||
+                            !isxdigit((unsigned char)src[2]) ||
+                            (ch = hexchar(src + 1)) == -1) {
+                                free(ret);
+                                return NULL;
+                        }
+                        *dst++ = ch;
+                        src += 2;
+                        break;
+                default:
+                        *dst++ = *src;
+                        break;
+                }
+        }
+        *dst = '\0';
+
+        return ret;
+}
+
+/*
+ * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI.
+ * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04
+ * Either user or path may be url-encoded (but not host or port).
+ * Caller must free returned user, host and path.
+ * Any of the pointer return arguments may be NULL (useful for syntax checking)
+ * but the scheme must always be specified.
+ * If user was not specified then *userp will be set to NULL.
+ * If port was not specified then *portp will be -1.
+ * If path was not specified then *pathp will be set to NULL.
+ * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri.
+ */
+int
+parse_uri(const char *scheme, const char *uri, char **userp, char **hostp,
+    int *portp, char **pathp)
+{
+        char *uridup, *cp, *tmp, ch;
+        char *user = NULL, *host = NULL, *path = NULL;
+        int port = -1, ret = -1;
+        size_t len;
+
+        len = strlen(scheme);
+        if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0)
+                return 1;
+        uri += len + 3;
+
+        if (userp != NULL)
+                *userp = NULL;
+        if (hostp != NULL)
+                *hostp = NULL;
+        if (portp != NULL)
+                *portp = -1;
+        if (pathp != NULL)
+                *pathp = NULL;
+
+        uridup = tmp = xstrdup(uri);
+
+        /* Extract optional ssh-info (username + connection params) */
+        if ((cp = strchr(tmp, '@')) != NULL) {
+                char *delim;
+
+                *cp = '\0';
+                /* Extract username and connection params */
+                if ((delim = strchr(tmp, ';')) != NULL) {
+                        /* Just ignore connection params for now */
+                        *delim = '\0';
+                }
+                if (*tmp == '\0') {
+                        /* Empty username */
+                        goto out;
+                }
+                if ((user = urldecode(tmp)) == NULL)
+                        goto out;
+                tmp = cp + 1;
+        }
+
+        /* Extract mandatory hostname */
+        if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0')
+                goto out;
+        host = xstrdup(cleanhostname(cp));
+        if (!valid_domain(host, 0, NULL))
+                goto out;
+
+        if (tmp != NULL && *tmp != '\0') {
+                if (ch == ':') {
+                        /* Convert and verify port. */
+                        if ((cp = strchr(tmp, '/')) != NULL)
+                                *cp = '\0';
+                        if ((port = a2port(tmp)) <= 0)
+                                goto out;
+                        tmp = cp ? cp + 1 : NULL;
+                }
+                if (tmp != NULL && *tmp != '\0') {
+                        /* Extract optional path */
+                        if ((path = urldecode(tmp)) == NULL)
+                                goto out;
+                }
+        }
+
+        /* Success */
+        if (userp != NULL) {
+                *userp = user;
+                user = NULL;
+        }
+        if (hostp != NULL) {
+                *hostp = host;
+                host = NULL;
+        }
+        if (portp != NULL)
+                *portp = port;
+        if (pathp != NULL) {
+                *pathp = path;
+                path = NULL;
+        }
+        ret = 0;
+ out:
+        free(uridup);
+        free(user);
+        free(host);
+        free(path);
+        return ret;
+}
+
 /* function to assist building execv() arguments */
 void
 addargs(arglist *args, char *fmt, ...)
@@ -774,16 +1081,19 @@ secure_permissions(struct stat *st, uid_t uid)
 }
 
 int
-tun_open(int tun, int mode)
+tun_open(int tun, int mode, char **ifname)
 {
 #if defined(CUSTOM_SYS_TUN_OPEN)
-        return (sys_tun_open(tun, mode));
+        return (sys_tun_open(tun, mode, ifname));
 #elif defined(SSH_TUN_OPENBSD)
         struct ifreq ifr;
         char name[100];
         int fd = -1, sock;
         const char *tunbase = "tun";
 
+        if (ifname != NULL)
+                *ifname = NULL;
+
         if (mode == SSH_TUNMODE_ETHERNET)
                 tunbase = "tap";
 
@@ -830,6 +1140,9 @@ tun_open(int tun, int mode)
                 }
         }
 
+        if (ifname != NULL)
+                *ifname = xstrdup(ifr.ifr_name);
+
         close(sock);
         return fd;
 
@@ -996,8 +1309,8 @@ ms_subtract_diff(struct timeval *start, int *ms)
 {
         struct timeval diff, finish;
 
-        gettimeofday(&finish, NULL);
-        timersub(&finish, start, &diff);        
+        monotime_tv(&finish);
+        timersub(&finish, start, &diff);
         *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000);
 }
 
@@ -1010,54 +1323,63 @@ ms_to_timeval(struct timeval *tv, int ms)
         tv->tv_usec = (ms % 1000) * 1000;
 }
 
-time_t
-monotime(void)
+void
+monotime_ts(struct timespec *ts)
 {
-#if defined(HAVE_CLOCK_GETTIME) && \
-    (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
-        struct timespec ts;
+        struct timeval tv;
+#if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \
+    defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME))
         static int gettime_failed = 0;
 
         if (!gettime_failed) {
-#if defined(CLOCK_BOOTTIME)
-                if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
-                        return (ts.tv_sec);
-#endif
-#if defined(CLOCK_MONOTONIC)
-                if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
-                        return (ts.tv_sec);
-#endif
+# ifdef CLOCK_BOOTTIME
+                if (clock_gettime(CLOCK_BOOTTIME, ts) == 0)
+                        return;
+# endif /* CLOCK_BOOTTIME */
+# ifdef CLOCK_MONOTONIC
+                if (clock_gettime(CLOCK_MONOTONIC, ts) == 0)
+                        return;
+# endif /* CLOCK_MONOTONIC */
+# ifdef CLOCK_REALTIME
+                /* Not monotonic, but we're almost out of options here. */
+                if (clock_gettime(CLOCK_REALTIME, ts) == 0)
+                        return;
+# endif /* CLOCK_REALTIME */
                 debug3("clock_gettime: %s", strerror(errno));
                 gettime_failed = 1;
         }
-#endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
+#endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */
+        gettimeofday(&tv, NULL);
+        ts->tv_sec = tv.tv_sec;
+        ts->tv_nsec = (long)tv.tv_usec * 1000;
+}
 
-        return time(NULL);
+void
+monotime_tv(struct timeval *tv)
+{
+        struct timespec ts;
+
+        monotime_ts(&ts);
+        tv->tv_sec = ts.tv_sec;
+        tv->tv_usec = ts.tv_nsec / 1000;
+}
+
+time_t
+monotime(void)
+{
+        struct timespec ts;
+
+        monotime_ts(&ts);
+        return ts.tv_sec;
 }
 
 double
 monotime_double(void)
 {
-#if defined(HAVE_CLOCK_GETTIME) && \
-    (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME))
         struct timespec ts;
-        static int gettime_failed = 0;
-
-        if (!gettime_failed) {
-#if defined(CLOCK_BOOTTIME)
-                if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0)
-                        return (ts.tv_sec + (double)ts.tv_nsec / 1000000000);
-#endif
-#if defined(CLOCK_MONOTONIC)
-                if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0)
-                        return (ts.tv_sec + (double)ts.tv_nsec / 1000000000);
-#endif
-                debug3("clock_gettime: %s", strerror(errno));
-                gettime_failed = 1;
-        }
-#endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */
 
-        return (double)time(NULL);
+        monotime_ts(&ts);
+        return ts.tv_sec + ((double)ts.tv_nsec / 1000000000);
 }
 
 void
@@ -1079,7 +1401,7 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
         struct timespec ts, rm;
 
         if (!timerisset(&bw->bwstart)) {
-                gettimeofday(&bw->bwstart, NULL);
+                monotime_tv(&bw->bwstart);
                 return;
         }
 
@@ -1087,7 +1409,7 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
         if (bw->lamt < bw->thresh)
                 return;
 
-        gettimeofday(&bw->bwend, NULL);
+        monotime_tv(&bw->bwend);
         timersub(&bw->bwend, &bw->bwstart, &bw->bwend);
         if (!timerisset(&bw->bwend))
                 return;
@@ -1121,7 +1443,7 @@ bandwidth_limit(struct bwlimit *bw, size_t read_len)
         }
 
         bw->lamt = 0;
-        gettimeofday(&bw->bwstart, NULL);
+        monotime_tv(&bw->bwstart);
 }
 
 /* Make a template filename for mk[sd]temp() */
@@ -1222,9 +1544,10 @@ unix_listener(const char *path, int backlog, int unlink_first)
 
         memset(&sunaddr, 0, sizeof(sunaddr));
         sunaddr.sun_family = AF_UNIX;
-        if (strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
-                error("%s: \"%s\" too long for Unix domain socket", __func__,
-                    path);
+        if (strlcpy(sunaddr.sun_path, path,
+            sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) {
+                error("%s: path \"%s\" too long for Unix domain socket",
+                    __func__, path);
                 errno = ENAMETOOLONG;
                 return -1;
         }
@@ -1232,7 +1555,7 @@ unix_listener(const char *path, int backlog, int unlink_first)
         sock = socket(PF_UNIX, SOCK_STREAM, 0);
         if (sock < 0) {
                 saved_errno = errno;
-                error("socket: %.100s", strerror(errno));
+                error("%s: socket: %.100s", __func__, strerror(errno));
                 errno = saved_errno;
                 return -1;
         }
@@ -1242,18 +1565,18 @@ unix_listener(const char *path, int backlog, int unlink_first)
         }
         if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) < 0) {
                 saved_errno = errno;
-                error("bind: %.100s", strerror(errno));
+                error("%s: cannot bind to path %s: %s",
+                    __func__, path, strerror(errno));
                 close(sock);
-                error("%s: cannot bind to path: %s", __func__, path);
                 errno = saved_errno;
                 return -1;
         }
         if (listen(sock, backlog) < 0) {
                 saved_errno = errno;
-                error("listen: %.100s", strerror(errno));
+                error("%s: cannot listen on path %s: %s",
+                    __func__, path, strerror(errno));
                 close(sock);
                 unlink(path);
-                error("%s: cannot listen on path: %s", __func__, path);
                 errno = saved_errno;
                 return -1;
         }
@@ -1467,158 +1790,6 @@ argv_assemble(int argc, char **argv)
         return ret;
 }
 
-/*
- * Runs command in a subprocess wuth a minimal environment.
- * Returns pid on success, 0 on failure.
- * The child stdout and stderr maybe captured, left attached or sent to
- * /dev/null depending on the contents of flags.
- * "tag" is prepended to log messages.
- * NB. "command" is only used for logging; the actual command executed is
- * av[0].
- */
-pid_t
-subprocess(const char *tag, struct passwd *pw, const char *command,
-    int ac, char **av, FILE **child, u_int flags)
-{
-        FILE *f = NULL;
-        struct stat st;
-        int fd, devnull, p[2], i;
-        pid_t pid;
-        char *cp, errmsg[512];
-        u_int envsize;
-        char **child_env;
-
-        if (child != NULL)
-                *child = NULL;
-
-        debug3("%s: %s command \"%s\" running as %s (flags 0x%x)", __func__,
-            tag, command, pw->pw_name, flags);
-
-        /* Check consistency */
-        if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
-            (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) {
-                error("%s: inconsistent flags", __func__);
-                return 0;
-        }
-        if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) {
-                error("%s: inconsistent flags/output", __func__);
-                return 0;
-        }
-
-        /*
-         * If executing an explicit binary, then verify the it exists
-         * and appears safe-ish to execute
-         */
-        if (*av[0] != '/') {
-                error("%s path is not absolute", tag);
-                return 0;
-        }
-        temporarily_use_uid(pw);
-        if (stat(av[0], &st) < 0) {
-                error("Could not stat %s \"%s\": %s", tag,
-                    av[0], strerror(errno));
-                restore_uid();
-                return 0;
-        }
-        if (safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) {
-                error("Unsafe %s \"%s\": %s", tag, av[0], errmsg);
-                restore_uid();
-                return 0;
-        }
-        /* Prepare to keep the child's stdout if requested */
-        if (pipe(p) != 0) {
-                error("%s: pipe: %s", tag, strerror(errno));
-                restore_uid();
-                return 0;
-        }
-        restore_uid();
-
-        switch ((pid = fork())) {
-        case -1: /* error */
-                error("%s: fork: %s", tag, strerror(errno));
-                close(p[0]);
-                close(p[1]);
-                return 0;
-        case 0: /* child */
-                /* Prepare a minimal environment for the child. */
-                envsize = 5;
-                child_env = xcalloc(sizeof(*child_env), envsize);
-                child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH);
-                child_set_env(&child_env, &envsize, "USER", pw->pw_name);
-                child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name);
-                child_set_env(&child_env, &envsize, "HOME", pw->pw_dir);
-                if ((cp = getenv("LANG")) != NULL)
-                        child_set_env(&child_env, &envsize, "LANG", cp);
-
-                for (i = 0; i < NSIG; i++)
-                        signal(i, SIG_DFL);
-
-                if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
-                        error("%s: open %s: %s", tag, _PATH_DEVNULL,
-                            strerror(errno));
-                        _exit(1);
-                }
-                if (dup2(devnull, STDIN_FILENO) == -1) {
-                        error("%s: dup2: %s", tag, strerror(errno));
-                        _exit(1);
-                }
-
-                /* Set up stdout as requested; leave stderr in place for now. */
-                fd = -1;
-                if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0)
-                        fd = p[1];
-                else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0)
-                        fd = devnull;
-                if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) {
-                        error("%s: dup2: %s", tag, strerror(errno));
-                        _exit(1);
-                }
-                closefrom(STDERR_FILENO + 1);
-
-                /* Don't use permanently_set_uid() here to avoid fatal() */
-                if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
-                        error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
-                            strerror(errno));
-                        _exit(1);
-                }
-                if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
-                        error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid,
-                            strerror(errno));
-                        _exit(1);
-                }
-                /* stdin is pointed to /dev/null at this point */
-                if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 &&
-                    dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
-                        error("%s: dup2: %s", tag, strerror(errno));
-                        _exit(1);
-                }
-
-                execve(av[0], av, child_env);
-                error("%s exec \"%s\": %s", tag, command, strerror(errno));
-                _exit(127);
-        default: /* parent */
-                break;
-        }
-
-        close(p[1]);
-        if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0)
-                close(p[0]);
-        else if ((f = fdopen(p[0], "r")) == NULL) {
-                error("%s: fdopen: %s", tag, strerror(errno));
-                close(p[0]);
-                /* Don't leave zombie child */
-                kill(pid, SIGTERM);
-                while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
-                        ;
-                return 0;
-        }
-        /* Success */
-        debug3("%s: %s pid %ld", __func__, tag, (long)pid);
-        if (child != NULL)
-                *child = f;
-        return pid;
-}
-
 /* Returns 0 if pid exited cleanly, non-zero otherwise */
 int
 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet)
@@ -1787,7 +1958,122 @@ child_set_env(char ***envp, u_int *envsizep, const char *name,
         }
 
         /* Allocate space and format the variable in the appropriate slot. */
+        /* XXX xasprintf */
         env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
         snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
 }
 
+/*
+ * Check and optionally lowercase a domain name, also removes trailing '.'
+ * Returns 1 on success and 0 on failure, storing an error message in errstr.
+ */
+int
+valid_domain(char *name, int makelower, const char **errstr)
+{
+        size_t i, l = strlen(name);
+        u_char c, last = '\0';
+        static char errbuf[256];
+
+        if (l == 0) {
+                strlcpy(errbuf, "empty domain name", sizeof(errbuf));
+                goto bad;
+        }
+        if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) {
+                snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" "
+                    "starts with invalid character", name);
+                goto bad;
+        }
+        for (i = 0; i < l; i++) {
+                c = tolower((u_char)name[i]);
+                if (makelower)
+                        name[i] = (char)c;
+                if (last == '.' && c == '.') {
+                        snprintf(errbuf, sizeof(errbuf), "domain name "
+                            "\"%.100s\" contains consecutive separators", name);
+                        goto bad;
+                }
+                if (c != '.' && c != '-' && !isalnum(c) &&
+                    c != '_') /* technically invalid, but common */ {
+                        snprintf(errbuf, sizeof(errbuf), "domain name "
+                            "\"%.100s\" contains invalid characters", name);
+                        goto bad;
+                }
+                last = c;
+        }
+        if (name[l - 1] == '.')
+                name[l - 1] = '\0';
+        if (errstr != NULL)
+                *errstr = NULL;
+        return 1;
+bad:
+        if (errstr != NULL)
+                *errstr = errbuf;
+        return 0;
+}
+
+const char *
+atoi_err(const char *nptr, int *val)
+{
+        const char *errstr = NULL;
+        long long num;
+
+        if (nptr == NULL || *nptr == '\0')
+                return "missing";
+        num = strtonum(nptr, 0, INT_MAX, &errstr);
+        if (errstr == NULL)
+                *val = (int)num;
+        return errstr;
+}
+
+int
+parse_absolute_time(const char *s, uint64_t *tp)
+{
+        struct tm tm;
+        time_t tt;
+        char buf[32], *fmt;
+
+        *tp = 0;
+
+        /*
+         * POSIX strptime says "The application shall ensure that there
+         * is white-space or other non-alphanumeric characters between
+         * any two conversion specifications" so arrange things this way.
+         */
+        switch (strlen(s)) {
+        case 8: /* YYYYMMDD */
+                fmt = "%Y-%m-%d";
+                snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
+                break;
+        case 12: /* YYYYMMDDHHMM */
+                fmt = "%Y-%m-%dT%H:%M";
+                snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s",
+                    s, s + 4, s + 6, s + 8, s + 10);
+                break;
+        case 14: /* YYYYMMDDHHMMSS */
+                fmt = "%Y-%m-%dT%H:%M:%S";
+                snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
+                    s, s + 4, s + 6, s + 8, s + 10, s + 12);
+                break;
+        default:
+                return SSH_ERR_INVALID_FORMAT;
+        }
+
+        memset(&tm, 0, sizeof(tm));
+        if (strptime(buf, fmt, &tm) == NULL)
+                return SSH_ERR_INVALID_FORMAT;
+        if ((tt = mktime(&tm)) < 0)
+                return SSH_ERR_INVALID_FORMAT;
+        /* success */
+        *tp = (uint64_t)tt;
+        return 0;
+}
+
+void
+format_absolute_time(uint64_t t, char *buf, size_t len)
+{
+        time_t tt = t > INT_MAX ? INT_MAX : t; /* XXX revisit in 2038 :P */
+        struct tm tm;
+
+        localtime_r(&tt, &tm);
+        strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm);
+}