chiark / gitweb /
nspawn: reset supplementary and main group id before entering nspawn
[elogind.git] / src / nspawn / nspawn.c
index 40b99343d79c4fb2574fe52ba3b0a142b730de0a..59171abff3cdb6c2e14ffbf50d9fb372baed362e 100644 (file)
@@ -46,6 +46,7 @@
 #include "log.h"
 #include "util.h"
 #include "mkdir.h"
+#include "macro.h"
 #include "audit.h"
 #include "missing.h"
 #include "cgroup-util.h"
@@ -92,7 +93,8 @@ static uint64_t arg_retain =
         (1ULL << CAP_SYS_NICE) |
         (1ULL << CAP_SYS_PTRACE) |
         (1ULL << CAP_SYS_TTY_CONFIG) |
-        (1ULL << CAP_SYS_RESOURCE);
+        (1ULL << CAP_SYS_RESOURCE) |
+        (1ULL << CAP_SYS_BOOT);
 
 static int help(void) {
 
@@ -269,10 +271,10 @@ static int mount_all(const char *dest) {
                 { "proc",      "/proc",     "proc",  NULL,       MS_NOSUID|MS_NOEXEC|MS_NODEV, true  },
                 { "/proc/sys", "/proc/sys", NULL,    NULL,       MS_BIND, true                       },   /* Bind mount first */
                 { NULL,        "/proc/sys", NULL,    NULL,       MS_BIND|MS_RDONLY|MS_REMOUNT, true  },   /* Then, make it r/o */
-                { "/sys",      "/sys",      NULL,    NULL,       MS_BIND,                      true  },   /* Bind mount first */
-                { NULL,        "/sys",      NULL,    NULL,       MS_BIND|MS_RDONLY|MS_REMOUNT, true  },   /* Then, make it r/o */
+                { "sysfs",     "/sys",      "sysfs", NULL,       MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, true  },
                 { "tmpfs",     "/dev",      "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME,     true  },
                 { "/dev/pts",  "/dev/pts",  NULL,    NULL,       MS_BIND,                      true  },
+                { "tmpfs",     "/dev/shm",  "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true  },
                 { "tmpfs",     "/run",      "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, true  },
 #ifdef HAVE_SELINUX
                 { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND,                      false },  /* Bind mount first */
@@ -282,9 +284,9 @@ static int mount_all(const char *dest) {
 
         unsigned k;
         int r = 0;
-        char *where;
 
         for (k = 0; k < ELEMENTSOF(mount_table); k++) {
+                char _cleanup_free_ *where = NULL;
                 int t;
 
                 if (asprintf(&where, "%s/%s", dest, mount_table[k].where) < 0) {
@@ -296,10 +298,9 @@ static int mount_all(const char *dest) {
                         break;
                 }
 
-                t = path_is_mount_point(where, false);
+                t = path_is_mount_point(where, true);
                 if (t < 0) {
                         log_error("Failed to detect whether %s is a mount point: %s", where, strerror(-t));
-                        free(where);
 
                         if (r == 0)
                                 r = t;
@@ -307,6 +308,10 @@ static int mount_all(const char *dest) {
                         continue;
                 }
 
+                /* Skip this entry if it is not a remount. */
+                if (mount_table[k].what && t > 0)
+                        continue;
+
                 mkdir_p_label(where, 0755);
 
                 if (mount(mount_table[k].what,
@@ -321,34 +326,67 @@ static int mount_all(const char *dest) {
                         if (r == 0)
                                 r = -errno;
                 }
-
-                free(where);
         }
 
         return r;
 }
 
 static int setup_timezone(const char *dest) {
-        char *where;
+        _cleanup_free_ char *where = NULL, *p = NULL, *q = NULL, *check = NULL, *what = NULL;
+        char *z, *y;
+        int r;
 
         assert(dest);
 
         /* Fix the timezone, if possible */
-        if (asprintf(&where, "%s/etc/localtime", dest) < 0)
+        r = readlink_malloc("/etc/localtime", &p);
+        if (r < 0) {
+                log_warning("/etc/localtime is not a symlink, not updating container timezone.");
+                return 0;
+        }
+
+        z = path_startswith(p, "../usr/share/zoneinfo/");
+        if (!z)
+                z = path_startswith(p, "/usr/share/zoneinfo/");
+        if (!z) {
+                log_warning("/etc/localtime does not point into /usr/share/zoneinfo/, not updating container timezone.");
+                return 0;
+        }
+
+        where = strappend(dest, "/etc/localtime");
+        if (!where)
                 return log_oom();
 
-        if (mount("/etc/localtime", where, "bind", MS_BIND, NULL) >= 0)
-                mount("/etc/localtime", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+        r = readlink_malloc(where, &q);
+        if (r >= 0) {
+                y = path_startswith(q, "../usr/share/zoneinfo/");
+                if (!y)
+                        y = path_startswith(q, "/usr/share/zoneinfo/");
 
-        free(where);
 
-        if (asprintf(&where, "%s/etc/timezone", dest) < 0)
+                /* Already pointing to the right place? Then do nothing .. */
+                if (y && streq(y, z))
+                        return 0;
+        }
+
+        check = strjoin(dest, "/usr/share/zoneinfo/", z, NULL);
+        if (!check)
                 return log_oom();
 
-        if (mount("/etc/timezone", where, "bind", MS_BIND, NULL) >= 0)
-                mount("/etc/timezone", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+        if (access(check, F_OK) < 0) {
+                log_warning("Timezone %s does not exist in container, not updating container timezone.", z);
+                return 0;
+        }
 
-        free(where);
+        what = strappend("../usr/share/zoneinfo/", z);
+        if (!what)
+                return log_oom();
+
+        unlink(where);
+        if (symlink(what, where) < 0) {
+                log_error("Failed to correct timezone of container: %m");
+                return 0;
+        }
 
         return 0;
 }
@@ -362,10 +400,12 @@ static int setup_resolv_conf(const char *dest) {
                 return 0;
 
         /* Fix resolv.conf, if possible */
-        if (asprintf(&where, "%s/etc/resolv.conf", dest) < 0) {
+        where = strappend(dest, "/etc/resolv.conf");
+        if (!where)
                 return log_oom();
-        }
 
+        /* We don't really care for the results of this really. If it
+         * fails, it fails, but meh... */
         if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0)
                 mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
 
@@ -374,6 +414,49 @@ static int setup_resolv_conf(const char *dest) {
         return 0;
 }
 
+static int setup_boot_id(const char *dest) {
+        char _cleanup_free_ *from = NULL, *to = NULL;
+        sd_id128_t rnd;
+        char as_uuid[37];
+        int r;
+
+        assert(dest);
+
+        /* Generate a new randomized boot ID, so that each boot-up of
+         * the container gets a new one */
+
+        from = strappend(dest, "/dev/proc-sys-kernel-random-boot-id");
+        to = strappend(dest, "/proc/sys/kernel/random/boot_id");
+        if (!from || !to)
+                return log_oom();
+
+        r = sd_id128_randomize(&rnd);
+        if (r < 0) {
+                log_error("Failed to generate random boot id: %s", strerror(-r));
+                return r;
+        }
+
+        snprintf(as_uuid, sizeof(as_uuid),
+                 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+                 SD_ID128_FORMAT_VAL(rnd));
+        char_array_0(as_uuid);
+
+        r = write_one_line_file(from, as_uuid);
+        if (r < 0) {
+                log_error("Failed to write boot id: %s", strerror(-r));
+                return r;
+        }
+
+        if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
+                log_error("Failed to bind mount boot id: %m");
+                r = -errno;
+        } else
+                mount(from, to, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
+
+        unlink(from);
+        return r;
+}
+
 static int copy_devnodes(const char *dest) {
 
         static const char devnodes[] =
@@ -383,12 +466,11 @@ static int copy_devnodes(const char *dest) {
                 "random\0"
                 "urandom\0"
                 "tty\0"
-                "ptmx\0"
-                "rtc0\0";
+                "ptmx\0";
 
         const char *d;
         int r = 0;
-        mode_t u;
+        mode_t _cleanup_umask_ u;
 
         assert(dest);
 
@@ -396,18 +478,13 @@ static int copy_devnodes(const char *dest) {
 
         NULSTR_FOREACH(d, devnodes) {
                 struct stat st;
-                char *from = NULL, *to = NULL;
+                char _cleanup_free_ *from = NULL, *to = NULL;
 
                 asprintf(&from, "/dev/%s", d);
                 asprintf(&to, "%s/dev/%s", dest, d);
 
                 if (!from || !to) {
-                        log_error("Failed to allocate devnode path");
-
-                        free(from);
-                        free(to);
-
-                        from = to = NULL;
+                        log_oom();
 
                         if (r == 0)
                                 r = -ENOMEM;
@@ -425,7 +502,7 @@ static int copy_devnodes(const char *dest) {
 
                 } else if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) {
 
-                        log_error("%s is not a char or block device, cannot copy.", from);
+                        log_error("%s is not a char or block device, cannot copy", from);
                         if (r == 0)
                                 r = -EIO;
 
@@ -435,21 +512,16 @@ static int copy_devnodes(const char *dest) {
                         if (r == 0)
                                 r = -errno;
                 }
-
-                free(from);
-                free(to);
         }
 
-        umask(u);
-
         return r;
 }
 
 static int setup_dev_console(const char *dest, const char *console) {
         struct stat st;
-        char *to = NULL;
+        char _cleanup_free_ *to = NULL;
         int r;
-        mode_t u;
+        mode_t _cleanup_umask_ u;
 
         assert(dest);
         assert(console);
@@ -458,25 +530,21 @@ static int setup_dev_console(const char *dest, const char *console) {
 
         if (stat(console, &st) < 0) {
                 log_error("Failed to stat %s: %m", console);
-                r = -errno;
-                goto finish;
+                return -errno;
 
         } else if (!S_ISCHR(st.st_mode)) {
-                log_error("/dev/console is not a char device.");
-                r = -EIO;
-                goto finish;
+                log_error("/dev/console is not a char device");
+                return -EIO;
         }
 
         r = chmod_and_chown(console, 0600, 0, 0);
         if (r < 0) {
                 log_error("Failed to correct access mode for TTY: %s", strerror(-r));
-                goto finish;
+                return r;
         }
 
-        if (asprintf(&to, "%s/dev/console", dest) < 0) {
-                r = log_oom();
-                goto finish;
-        }
+        if (asprintf(&to, "%s/dev/console", dest) < 0)
+                return log_oom();
 
         /* We need to bind mount the right tty to /dev/console since
          * ptys can only exist on pts file systems. To have something
@@ -487,27 +555,21 @@ static int setup_dev_console(const char *dest, const char *console) {
 
         if (mknod(to, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) {
                 log_error("mknod() for /dev/console failed: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
         if (mount(console, to, "bind", MS_BIND, NULL) < 0) {
                 log_error("Bind mount for /dev/console failed: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
-finish:
-        free(to);
-        umask(u);
-
-        return r;
+        return 0;
 }
 
 static int setup_kmsg(const char *dest, int kmsg_socket) {
-        char *from = NULL, *to = NULL;
+        char _cleanup_free_ *from = NULL, *to = NULL;
         int r, fd, k;
-        mode_t u;
+        mode_t _cleanup_umask_ u;
         union {
                 struct cmsghdr cmsghdr;
                 uint8_t buf[CMSG_SPACE(sizeof(int))];
@@ -527,39 +589,30 @@ static int setup_kmsg(const char *dest, int kmsg_socket) {
          * that writing blocks when nothing is reading. In order to
          * avoid any problems with containers deadlocking due to this
          * we simply make /dev/kmsg unavailable to the container. */
-        if (asprintf(&from, "%s/dev/kmsg", dest) < 0) {
-                r = log_oom();
-                goto finish;
-        }
-
-        if (asprintf(&to, "%s/proc/kmsg", dest) < 0) {
-                r = log_oom();
-                goto finish;
-        }
+        if (asprintf(&from, "%s/dev/kmsg", dest) < 0 ||
+            asprintf(&to, "%s/proc/kmsg", dest) < 0)
+                return log_oom();
 
         if (mkfifo(from, 0600) < 0) {
                 log_error("mkfifo() for /dev/kmsg failed: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
         r = chmod_and_chown(from, 0600, 0, 0);
         if (r < 0) {
                 log_error("Failed to correct access mode for /dev/kmsg: %s", strerror(-r));
-                goto finish;
+                return r;
         }
 
         if (mount(from, to, "bind", MS_BIND, NULL) < 0) {
                 log_error("Bind mount for /proc/kmsg failed: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
         fd = open(from, O_RDWR|O_NDELAY|O_CLOEXEC);
         if (fd < 0) {
                 log_error("Failed to open fifo: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
         zero(mh);
@@ -583,19 +636,12 @@ static int setup_kmsg(const char *dest, int kmsg_socket) {
 
         if (k < 0) {
                 log_error("Failed to send FIFO fd: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
         /* And now make the FIFO unavailable as /dev/kmsg... */
         unlink(from);
-
-finish:
-        free(from);
-        free(to);
-        umask(u);
-
-        return r;
+        return 0;
 }
 
 static int setup_hostname(void) {
@@ -622,58 +668,58 @@ static int setup_hostname(void) {
 
 static int setup_journal(const char *directory) {
         sd_id128_t machine_id;
-        char *p = NULL, *b = NULL, *l, *q = NULL, *d = NULL;
+        char _cleanup_free_ *p = NULL, *b = NULL, *q = NULL, *d = NULL;
+        char *id;
         int r;
 
         if (arg_link_journal == LINK_NO)
                 return 0;
 
         p = strappend(directory, "/etc/machine-id");
-        if (!p) {
-                r = log_oom();
-                goto finish;
-        }
+        if (!p)
+                return log_oom();
 
         r = read_one_line_file(p, &b);
-        if (r == -ENOENT && arg_link_journal == LINK_AUTO) {
-                r = 0;
-                goto finish;
-        } else if (r < 0) {
-                log_error("Failed to read machine ID: %s", strerror(-r));
+        if (r == -ENOENT && arg_link_journal == LINK_AUTO)
+                return 0;
+        else if (r < 0) {
+                log_error("Failed to read machine ID from %s: %s", p, strerror(-r));
                 return r;
         }
 
-        l = strstrip(b);
-        if (isempty(l) && arg_link_journal == LINK_AUTO) {
-                r = 0;
-                goto finish;
-        }
+        id = strstrip(b);
+        if (isempty(id) && arg_link_journal == LINK_AUTO)
+                return 0;
 
-        /* Verify validaty */
-        r = sd_id128_from_string(l, &machine_id);
+        /* Verify validity */
+        r = sd_id128_from_string(id, &machine_id);
         if (r < 0) {
-                log_error("Failed to parse machine ID: %s", strerror(-r));
-                goto finish;
+                log_error("Failed to parse machine ID from %s: %s", p, strerror(-r));
+                return r;
         }
 
         free(p);
-        p = strappend("/var/log/journal/", l);
-        q = strjoin(directory, "/var/log/journal/", l, NULL);
-        if (!p || !q) {
-                r = log_oom();
-                goto finish;
+        p = strappend("/var/log/journal/", id);
+        q = strjoin(directory, "/var/log/journal/", id, NULL);
+        if (!p || !q)
+                return log_oom();
+
+        if (path_is_mount_point(p, false) > 0) {
+                if (arg_link_journal != LINK_AUTO) {
+                        log_error("%s: already a mount point, refusing to use for journal", p);
+                        return -EEXIST;
+                }
+
+                return 0;
         }
 
-        if (path_is_mount_point(p, false) > 0 ||
-            path_is_mount_point(q, false) > 0) {
+        if (path_is_mount_point(q, false) > 0) {
                 if (arg_link_journal != LINK_AUTO) {
-                        log_error("Journal already a mount point, refusing.");
-                        r = -EEXIST;
-                        goto finish;
+                        log_error("%s: already a mount point, refusing to use for journal", q);
+                        return -EEXIST;
                 }
 
-                r = 0;
-                goto finish;
+                return 0;
         }
 
         r = readlink_and_make_absolute(p, &d);
@@ -682,89 +728,74 @@ static int setup_journal(const char *directory) {
                      arg_link_journal == LINK_AUTO) &&
                     path_equal(d, q)) {
 
-                        mkdir_p(q, 0755);
-
-                        r = 0;
-                        goto finish;
+                        r = mkdir_p(q, 0755);
+                        if (r < 0)
+                                log_warning("failed to create directory %s: %m", q);
+                        return 0;
                 }
 
                 if (unlink(p) < 0) {
                         log_error("Failed to remove symlink %s: %m", p);
-                        r = -errno;
-                        goto finish;
+                        return -errno;
                 }
         } else if (r == -EINVAL) {
 
                 if (arg_link_journal == LINK_GUEST &&
                     rmdir(p) < 0) {
 
-                        if (errno == ENOTDIR)
-                                log_error("%s already exists and is neither symlink nor directory.", p);
-                        else {
+                        if (errno == ENOTDIR) {
+                                log_error("%s already exists and is neither a symlink nor a directory", p);
+                                return r;
+                        } else {
                                 log_error("Failed to remove %s: %m", p);
-                                r = -errno;
+                                return -errno;
                         }
-
-                        goto finish;
                 }
         } else if (r != -ENOENT) {
                 log_error("readlink(%s) failed: %m", p);
-                goto finish;
+                return r;
         }
 
         if (arg_link_journal == LINK_GUEST) {
 
                 if (symlink(q, p) < 0) {
                         log_error("Failed to symlink %s to %s: %m", q, p);
-                        r = -errno;
-                        goto finish;
+                        return -errno;
                 }
 
-                mkdir_p(q, 0755);
-
-                r = 0;
-                goto finish;
+                r = mkdir_p(q, 0755);
+                if (r < 0)
+                        log_warning("failed to create directory %s: %m", q);
+                return 0;
         }
 
         if (arg_link_journal == LINK_HOST) {
                 r = mkdir_p(p, 0755);
                 if (r < 0) {
                         log_error("Failed to create %s: %m", p);
-                        goto finish;
+                        return r;
                 }
 
-        } else if (access(p, F_OK) < 0) {
-                r = 0;
-                goto finish;
-        }
+        } else if (access(p, F_OK) < 0)
+                return 0;
 
         if (dir_is_empty(q) == 0) {
                 log_error("%s not empty.", q);
-                r = -ENOTEMPTY;
-                goto finish;
+                return -ENOTEMPTY;
         }
 
         r = mkdir_p(q, 0755);
         if (r < 0) {
                 log_error("Failed to create %s: %m", q);
-                goto finish;
+                return r;
         }
 
         if (mount(p, q, "bind", MS_BIND, NULL) < 0) {
                 log_error("Failed to bind mount journal from host into guest: %m");
-                r = -errno;
-                goto finish;
+                return -errno;
         }
 
-        r = 0;
-
-finish:
-        free(p);
-        free(q);
-        free(d);
-        free(b);
-        return r;
-
+        return 0;
 }
 
 static int drop_capabilities(void) {
@@ -1108,11 +1139,6 @@ int main(int argc, char *argv[]) {
         cfmakeraw(&raw_attr);
         raw_attr.c_lflag &= ~ECHO;
 
-        if (tcsetattr(STDIN_FILENO, TCSANOW, &raw_attr) < 0) {
-                log_error("Failed to set terminal attributes: %m");
-                goto finish;
-        }
-
         if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
                 log_error("Failed to create kmsg socket pair");
                 goto finish;
@@ -1122,229 +1148,294 @@ int main(int argc, char *argv[]) {
         sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
         assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
 
-        pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
-        if (pid < 0) {
-                if (errno == EINVAL)
-                        log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
-                else
-                        log_error("clone() failed: %m");
+        for (;;) {
+                siginfo_t status;
 
-                goto finish;
-        }
+                if (tcsetattr(STDIN_FILENO, TCSANOW, &raw_attr) < 0) {
+                        log_error("Failed to set terminal attributes: %m");
+                        goto finish;
+                }
 
-        if (pid == 0) {
-                /* child */
-
-                const char *home = NULL;
-                uid_t uid = (uid_t) -1;
-                gid_t gid = (gid_t) -1;
-                const char *envp[] = {
-                        "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
-                        "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
-                        NULL, /* TERM */
-                        NULL, /* HOME */
-                        NULL, /* USER */
-                        NULL, /* LOGNAME */
-                        NULL, /* container_uuid */
-                        NULL
-                };
-
-                envp[2] = strv_find_prefix(environ, "TERM=");
+                pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWIPC|CLONE_NEWNS|CLONE_NEWPID|CLONE_NEWUTS|(arg_private_network ? CLONE_NEWNET : 0), NULL);
+                if (pid < 0) {
+                        if (errno == EINVAL)
+                                log_error("clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
+                        else
+                                log_error("clone() failed: %m");
 
-                close_nointr_nofail(master);
+                        goto finish;
+                }
 
-                close_nointr(STDIN_FILENO);
-                close_nointr(STDOUT_FILENO);
-                close_nointr(STDERR_FILENO);
+                if (pid == 0) {
+                        /* child */
 
-                close_all_fds(&kmsg_socket_pair[1], 1);
+                        const char *home = NULL;
+                        uid_t uid = (uid_t) -1;
+                        gid_t gid = (gid_t) -1;
+                        const char *envp[] = {
+                                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+                                "container=systemd-nspawn", /* LXC sets container=lxc, so follow the scheme here */
+                                NULL, /* TERM */
+                                NULL, /* HOME */
+                                NULL, /* USER */
+                                NULL, /* LOGNAME */
+                                NULL, /* container_uuid */
+                                NULL
+                        };
 
-                reset_all_signal_handlers();
+                        envp[2] = strv_find_prefix(environ, "TERM=");
 
-                assert_se(sigemptyset(&mask) == 0);
-                assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
+                        close_nointr_nofail(master);
 
-                if (open_terminal(console, O_RDWR) != STDIN_FILENO ||
-                    dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
-                    dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO)
-                        goto child_fail;
+                        close_nointr(STDIN_FILENO);
+                        close_nointr(STDOUT_FILENO);
+                        close_nointr(STDERR_FILENO);
 
-                if (setsid() < 0) {
-                        log_error("setsid() failed: %m");
-                        goto child_fail;
-                }
+                        close_all_fds(&kmsg_socket_pair[1], 1);
 
-                if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
-                        log_error("PR_SET_PDEATHSIG failed: %m");
-                        goto child_fail;
-                }
+                        reset_all_signal_handlers();
 
-                /* Mark everything as slave, so that we still
-                 * receive mounts from the real root, but don't
-                 * propagate mounts to the real root. */
-                if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
-                        log_error("MS_SLAVE|MS_REC failed: %m");
-                        goto child_fail;
-                }
+                        assert_se(sigemptyset(&mask) == 0);
+                        assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 
-                /* Turn directory into bind mount */
-                if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
-                        log_error("Failed to make bind mount.");
-                        goto child_fail;
-                }
+                        if (open_terminal(console, O_RDWR) != STDIN_FILENO ||
+                            dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||
+                            dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO)
+                                goto child_fail;
 
-                if (arg_read_only)
-                        if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) {
-                                log_error("Failed to make read-only.");
+                        if (setsid() < 0) {
+                                log_error("setsid() failed: %m");
                                 goto child_fail;
                         }
 
-                if (mount_all(arg_directory) < 0)
-                        goto child_fail;
-
-                if (copy_devnodes(arg_directory) < 0)
-                        goto child_fail;
-
-                dev_setup(arg_directory);
-
-                if (setup_dev_console(arg_directory, console) < 0)
-                        goto child_fail;
-
-                if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
-                        goto child_fail;
+                        if (prctl(PR_SET_PDEATHSIG, SIGKILL) < 0) {
+                                log_error("PR_SET_PDEATHSIG failed: %m");
+                                goto child_fail;
+                        }
 
-                close_nointr_nofail(kmsg_socket_pair[1]);
+                        /* Mark everything as slave, so that we still
+                         * receive mounts from the real root, but don't
+                         * propagate mounts to the real root. */
+                        if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
+                                log_error("MS_SLAVE|MS_REC failed: %m");
+                                goto child_fail;
+                        }
 
-                if (setup_timezone(arg_directory) < 0)
-                        goto child_fail;
+                        /* Turn directory into bind mount */
+                        if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REC, NULL) < 0) {
+                                log_error("Failed to make bind mount.");
+                                goto child_fail;
+                        }
 
-                if (setup_resolv_conf(arg_directory) < 0)
-                        goto child_fail;
+                        if (arg_read_only)
+                                if (mount(arg_directory, arg_directory, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY|MS_REC, NULL) < 0) {
+                                        log_error("Failed to make read-only.");
+                                        goto child_fail;
+                                }
 
-                if (setup_journal(arg_directory) < 0)
-                        goto child_fail;
+                        if (mount_all(arg_directory) < 0)
+                                goto child_fail;
 
-                if (chdir(arg_directory) < 0) {
-                        log_error("chdir(%s) failed: %m", arg_directory);
-                        goto child_fail;
-                }
+                        if (copy_devnodes(arg_directory) < 0)
+                                goto child_fail;
 
-                if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) {
-                        log_error("mount(MS_MOVE) failed: %m");
-                        goto child_fail;
-                }
+                        dev_setup(arg_directory);
 
-                if (chroot(".") < 0) {
-                        log_error("chroot() failed: %m");
-                        goto child_fail;
-                }
+                        if (setup_dev_console(arg_directory, console) < 0)
+                                goto child_fail;
 
-                if (chdir("/") < 0) {
-                        log_error("chdir() failed: %m");
-                        goto child_fail;
-                }
+                        if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
+                                goto child_fail;
 
-                umask(0022);
+                        close_nointr_nofail(kmsg_socket_pair[1]);
 
-                loopback_setup();
+                        if (setup_boot_id(arg_directory) < 0)
+                                goto child_fail;
 
-                if (drop_capabilities() < 0) {
-                        log_error("drop_capabilities() failed: %m");
-                        goto child_fail;
-                }
+                        if (setup_timezone(arg_directory) < 0)
+                                goto child_fail;
 
-                if (arg_user) {
+                        if (setup_resolv_conf(arg_directory) < 0)
+                                goto child_fail;
 
-                        if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
-                                log_error("get_user_creds() failed: %m");
+                        if (setup_journal(arg_directory) < 0)
                                 goto child_fail;
-                        }
 
-                        if (mkdir_parents_label(home, 0775) < 0) {
-                                log_error("mkdir_parents_label() failed: %m");
+                        if (chdir(arg_directory) < 0) {
+                                log_error("chdir(%s) failed: %m", arg_directory);
                                 goto child_fail;
                         }
 
-                        if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
-                                log_error("mkdir_safe_label() failed: %m");
+                        if (mount(arg_directory, "/", NULL, MS_MOVE, NULL) < 0) {
+                                log_error("mount(MS_MOVE) failed: %m");
                                 goto child_fail;
                         }
 
-                        if (initgroups((const char*)arg_user, gid) < 0) {
-                                log_error("initgroups() failed: %m");
+                        if (chroot(".") < 0) {
+                                log_error("chroot() failed: %m");
                                 goto child_fail;
                         }
 
-                        if (setresgid(gid, gid, gid) < 0) {
-                                log_error("setregid() failed: %m");
+                        if (chdir("/") < 0) {
+                                log_error("chdir() failed: %m");
                                 goto child_fail;
                         }
 
-                        if (setresuid(uid, uid, uid) < 0) {
-                                log_error("setreuid() failed: %m");
+                        umask(0022);
+
+                        loopback_setup();
+
+                        if (drop_capabilities() < 0) {
+                                log_error("drop_capabilities() failed: %m");
                                 goto child_fail;
                         }
-                }
 
-                if ((asprintf((char**)(envp + 3), "HOME=%s", home ? home: "/root") < 0) ||
-                    (asprintf((char**)(envp + 4), "USER=%s", arg_user ? arg_user : "root") < 0) ||
-                    (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
-                    log_oom();
-                    goto child_fail;
-                }
+                        if (arg_user) {
+
+                                /* Note that this resolves user names
+                                 * inside the container, and hence
+                                 * accesses the NSS modules from the
+                                 * container and not the host. This is
+                                 * a bit weird... */
+
+                                if (get_user_creds((const char**)&arg_user, &uid, &gid, &home, NULL) < 0) {
+                                        log_error("get_user_creds() failed: %m");
+                                        goto child_fail;
+                                }
+
+                                if (mkdir_parents_label(home, 0775) < 0) {
+                                        log_error("mkdir_parents_label() failed: %m");
+                                        goto child_fail;
+                                }
+
+                                if (mkdir_safe_label(home, 0775, uid, gid) < 0) {
+                                        log_error("mkdir_safe_label() failed: %m");
+                                        goto child_fail;
+                                }
+
+                                if (initgroups((const char*)arg_user, gid) < 0) {
+                                        log_error("initgroups() failed: %m");
+                                        goto child_fail;
+                                }
+
+                                if (setresgid(gid, gid, gid) < 0) {
+                                        log_error("setregid() failed: %m");
+                                        goto child_fail;
+                                }
+
+                                if (setresuid(uid, uid, uid) < 0) {
+                                        log_error("setreuid() failed: %m");
+                                        goto child_fail;
+                                }
+                        } else {
+                                /* Reset everything fully to 0, just in case */
+
+                                if (setgroups(0, NULL) < 0) {
+                                        log_error("setgroups() failed: %m");
+                                        goto child_fail;
+                                }
+
+                                if (setresgid(0, 0, 0) < 0) {
+                                        log_error("setregid() failed: %m");
+                                        goto child_fail;
+                                }
 
-                if (arg_uuid) {
-                        if (asprintf((char**)(envp + 6), "container_uuid=%s", arg_uuid) < 0) {
+                                if (setresuid(0, 0, 0) < 0) {
+                                        log_error("setreuid() failed: %m");
+                                        goto child_fail;
+                                }
+                        }
+
+                        if ((asprintf((char**)(envp + 3), "HOME=%s", home ? home: "/root") < 0) ||
+                            (asprintf((char**)(envp + 4), "USER=%s", arg_user ? arg_user : "root") < 0) ||
+                            (asprintf((char**)(envp + 5), "LOGNAME=%s", arg_user ? arg_user : "root") < 0)) {
                                 log_oom();
                                 goto child_fail;
                         }
-                }
 
-                setup_hostname();
+                        if (arg_uuid) {
+                                if (asprintf((char**)(envp + 6), "container_uuid=%s", arg_uuid) < 0) {
+                                        log_oom();
+                                        goto child_fail;
+                                }
+                        }
 
-                if (arg_boot) {
-                        char **a;
-                        size_t l;
+                        setup_hostname();
 
-                        /* Automatically search for the init system */
+                        if (arg_boot) {
+                                char **a;
+                                size_t l;
 
-                        l = 1 + argc - optind;
-                        a = newa(char*, l + 1);
-                        memcpy(a + 1, argv + optind, l * sizeof(char*));
+                                /* Automatically search for the init system */
 
-                        a[0] = (char*) "/usr/lib/systemd/systemd";
-                        execve(a[0], a, (char**) envp);
+                                l = 1 + argc - optind;
+                                a = newa(char*, l + 1);
+                                memcpy(a + 1, argv + optind, l * sizeof(char*));
 
-                        a[0] = (char*) "/lib/systemd/systemd";
-                        execve(a[0], a, (char**) envp);
+                                a[0] = (char*) "/usr/lib/systemd/systemd";
+                                execve(a[0], a, (char**) envp);
 
-                        a[0] = (char*) "/sbin/init";
-                        execve(a[0], a, (char**) envp);
-                } else if (argc > optind)
-                        execvpe(argv[optind], argv + optind, (char**) envp);
-                else {
-                        chdir(home ? home : "/root");
-                        execle("/bin/bash", "-bash", NULL, (char**) envp);
+                                a[0] = (char*) "/lib/systemd/systemd";
+                                execve(a[0], a, (char**) envp);
+
+                                a[0] = (char*) "/sbin/init";
+                                execve(a[0], a, (char**) envp);
+                        } else if (argc > optind)
+                                execvpe(argv[optind], argv + optind, (char**) envp);
+                        else {
+                                chdir(home ? home : "/root");
+                                execle("/bin/bash", "-bash", NULL, (char**) envp);
+                        }
+
+                        log_error("execv() failed: %m");
+
+                child_fail:
+                        _exit(EXIT_FAILURE);
                 }
 
-                log_error("execv() failed: %m");
+                if (process_pty(master, &mask) < 0)
+                        goto finish;
 
-        child_fail:
-                _exit(EXIT_FAILURE);
-        }
 
-        if (process_pty(master, &mask) < 0)
-                goto finish;
+                if (saved_attr_valid)
+                        tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
 
-        if (saved_attr_valid) {
-                tcsetattr(STDIN_FILENO, TCSANOW, &saved_attr);
-                saved_attr_valid = false;
-        }
+                r = wait_for_terminate(pid, &status);
+                if (r < 0) {
+                        r = EXIT_FAILURE;
+                        break;
+                }
 
-        r = wait_for_terminate_and_warn(argc > optind ? argv[optind] : "bash", pid);
+                if (status.si_code == CLD_EXITED) {
+                        if (status.si_status != 0) {
+                                log_error("Container failed with error code %i.", status.si_status);
+                                r = status.si_status;
+                                break;
+                        }
+
+                        log_debug("Container exited successfully.");
+                        break;
+                } else if (status.si_code == CLD_KILLED &&
+                           status.si_status == SIGINT) {
+                        log_info("Container has been shut down.");
+                        r = 0;
+                        break;
+                } else if (status.si_code == CLD_KILLED &&
+                           status.si_status == SIGHUP) {
+                        log_info("Container is being rebooted.");
+                        continue;
+                } else if (status.si_code == CLD_KILLED ||
+                           status.si_code == CLD_DUMPED) {
 
-        if (r < 0)
-                r = EXIT_FAILURE;
+                        log_error("Container terminated by signal %s.", signal_to_string(status.si_status));
+                        r = EXIT_FAILURE;
+                        break;
+                } else {
+                        log_error("Container failed due to unknown reason.");
+                        r = EXIT_FAILURE;
+                        break;
+                }
+        }
 
 finish:
         if (saved_attr_valid)