chiark / gitweb /
nspawn: pass the container's init PID out via sd_notify()
[elogind.git] / src / nspawn / nspawn.c
index fed150e364984ddf80d4b6a33215f4ec87682ea3..2bda27edf07472a5e36650b488c2b43afbc5054b 100644 (file)
@@ -31,7 +31,6 @@
 #include <stdio.h>
 #include <errno.h>
 #include <sys/prctl.h>
-#include <sys/capability.h>
 #include <getopt.h>
 #include <termios.h>
 #include <sys/signalfd.h>
 #include "base-filesystem.h"
 #include "barrier.h"
 #include "event-util.h"
+#include "capability.h"
+#include "cap-list.h"
+#include "btrfs-util.h"
+#include "machine-image.h"
+#include "list.h"
+#include "in-addr-util.h"
+#include "fw-util.h"
+#include "local-addresses.h"
 
 #ifdef HAVE_SECCOMP
 #include "seccomp-util.h"
 #endif
 
+typedef struct ExposePort {
+        int protocol;
+        uint16_t host_port;
+        uint16_t container_port;
+        LIST_FIELDS(struct ExposePort, ports);
+} ExposePort;
+
 typedef enum ContainerStatus {
         CONTAINER_TERMINATED,
         CONTAINER_REBOOTED
@@ -114,6 +128,7 @@ typedef enum Volatile {
 } Volatile;
 
 static char *arg_directory = NULL;
+static char *arg_template = NULL;
 static char *arg_user = NULL;
 static sd_id128_t arg_uuid = {};
 static char *arg_machine = NULL;
@@ -123,6 +138,7 @@ static const char *arg_slice = NULL;
 static bool arg_private_network = false;
 static bool arg_read_only = false;
 static bool arg_boot = false;
+static bool arg_ephemeral = false;
 static LinkJournal arg_link_journal = LINK_AUTO;
 static bool arg_link_journal_try = false;
 static uint64_t arg_retain =
@@ -165,8 +181,9 @@ static char **arg_network_macvlan = NULL;
 static bool arg_network_veth = false;
 static const char *arg_network_bridge = NULL;
 static unsigned long arg_personality = 0xffffffffLU;
-static const char *arg_image = NULL;
+static char *arg_image = NULL;
 static Volatile arg_volatile = VOLATILE_NO;
+static ExposePort *arg_expose_ports = NULL;
 
 static void help(void) {
         printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
@@ -175,7 +192,11 @@ static void help(void) {
                "     --version              Print version string\n"
                "  -q --quiet                Do not show status information\n"
                "  -D --directory=PATH       Root directory for the container\n"
-               "  -i --image=PATH           File system device or image for the container\n"
+               "     --template=PATH        Initialize root directory from template directory,\n"
+               "                            if missing\n"
+               "  -x --ephemeral            Run container with snapshot of root directory, and\n"
+               "                            remove it after exit\n"
+               "  -i --image=PATH           File system device or disk image for the container\n"
                "  -b --boot                 Boot up full system (i.e. invoke init)\n"
                "  -u --user=USER            Run the command under specified user or uid\n"
                "  -M --machine=NAME         Set the machine name for the container\n"
@@ -188,12 +209,14 @@ static void help(void) {
                "     --network-macvlan=INTERFACE\n"
                "                            Create a macvlan network interface based on an\n"
                "                            existing network interface to the container\n"
-               "     --network-veth         Add a virtual ethernet connection between host\n"
+               "  -n --network-veth         Add a virtual ethernet connection between host\n"
                "                            and container\n"
                "     --network-bridge=INTERFACE\n"
                "                            Add a virtual ethernet connection between host\n"
                "                            and container and add it to an existing bridge on\n"
                "                            the host\n"
+               "  -p --port=[PROTOCOL:]HOSTPORT[:CONTAINERPORT]\n"
+               "                            Expose a container IP port on the host\n"
                "  -Z --selinux-context=SECLABEL\n"
                "                            Set the SELinux security context to be used by\n"
                "                            processes in the container\n"
@@ -216,8 +239,29 @@ static void help(void) {
                "     --register=BOOLEAN     Register container as machine\n"
                "     --keep-unit            Do not register a scope for the machine, reuse\n"
                "                            the service unit nspawn is running in\n"
-               "     --volatile[=MODE]      Run the system in volatile mode\n",
-               program_invocation_short_name);
+               "     --volatile[=MODE]      Run the system in volatile mode\n"
+               , program_invocation_short_name);
+}
+
+static int set_sanitized_path(char **b, const char *path) {
+        char *p;
+
+        assert(b);
+        assert(path);
+
+        p = canonicalize_file_name(path);
+        if (!p) {
+                if (errno != ENOENT)
+                        return -errno;
+
+                p = path_make_absolute_cwd(path);
+                if (!p)
+                        return -ENOMEM;
+        }
+
+        free(*b);
+        *b = path_kill_slashes(p);
+        return 0;
 }
 
 static int parse_argv(int argc, char *argv[]) {
@@ -239,16 +283,18 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_KEEP_UNIT,
                 ARG_NETWORK_INTERFACE,
                 ARG_NETWORK_MACVLAN,
-                ARG_NETWORK_VETH,
                 ARG_NETWORK_BRIDGE,
                 ARG_PERSONALITY,
                 ARG_VOLATILE,
+                ARG_TEMPLATE,
         };
 
         static const struct option options[] = {
                 { "help",                  no_argument,       NULL, 'h'                   },
                 { "version",               no_argument,       NULL, ARG_VERSION           },
                 { "directory",             required_argument, NULL, 'D'                   },
+                { "template",              required_argument, NULL, ARG_TEMPLATE          },
+                { "ephemeral",             no_argument,       NULL, 'x'                   },
                 { "user",                  required_argument, NULL, 'u'                   },
                 { "private-network",       no_argument,       NULL, ARG_PRIVATE_NETWORK   },
                 { "boot",                  no_argument,       NULL, 'b'                   },
@@ -271,11 +317,12 @@ static int parse_argv(int argc, char *argv[]) {
                 { "keep-unit",             no_argument,       NULL, ARG_KEEP_UNIT         },
                 { "network-interface",     required_argument, NULL, ARG_NETWORK_INTERFACE },
                 { "network-macvlan",       required_argument, NULL, ARG_NETWORK_MACVLAN   },
-                { "network-veth",          no_argument,       NULL, ARG_NETWORK_VETH      },
+                { "network-veth",          no_argument,       NULL, 'n'                   },
                 { "network-bridge",        required_argument, NULL, ARG_NETWORK_BRIDGE    },
                 { "personality",           required_argument, NULL, ARG_PERSONALITY       },
                 { "image",                 required_argument, NULL, 'i'                   },
                 { "volatile",              optional_argument, NULL, ARG_VOLATILE          },
+                { "port",                  required_argument, NULL, 'p'                   },
                 {}
         };
 
@@ -285,7 +332,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 0);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "+hD:u:bL:M:jS:Z:qi:", options, NULL)) >= 0)
+        while ((c = getopt_long(argc, argv, "+hD:u:bL:M:jS:Z:qi:xp:n", options, NULL)) >= 0)
 
                 switch (c) {
 
@@ -299,17 +346,28 @@ static int parse_argv(int argc, char *argv[]) {
                         return 0;
 
                 case 'D':
-                        free(arg_directory);
-                        arg_directory = canonicalize_file_name(optarg);
-                        if (!arg_directory) {
-                                log_error_errno(errno, "Invalid root directory: %m");
-                                return -ENOMEM;
-                        }
+                        r = set_sanitized_path(&arg_directory, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid root directory: %m");
+
+                        break;
+
+                case ARG_TEMPLATE:
+                        r = set_sanitized_path(&arg_template, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid template directory: %m");
 
                         break;
 
                 case 'i':
-                        arg_image = optarg;
+                        r = set_sanitized_path(&arg_image, optarg);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid image path: %m");
+
+                        break;
+
+                case 'x':
+                        arg_ephemeral = true;
                         break;
 
                 case 'u':
@@ -325,7 +383,7 @@ static int parse_argv(int argc, char *argv[]) {
 
                         /* fall through */
 
-                case ARG_NETWORK_VETH:
+                case 'n':
                         arg_network_veth = true;
                         arg_private_network = true;
                         break;
@@ -368,15 +426,13 @@ static int parse_argv(int argc, char *argv[]) {
                                 free(arg_machine);
                                 arg_machine = NULL;
                         } else {
-
-                                if (!hostname_is_valid(optarg)) {
+                                if (!machine_name_is_valid(optarg)) {
                                         log_error("Invalid machine name: %s", optarg);
                                         return -EINVAL;
                                 }
 
-                                free(arg_machine);
-                                arg_machine = strdup(optarg);
-                                if (!arg_machine)
+                                r = free_and_strdup(&arg_machine, optarg);
+                                if (r < 0)
                                         return log_oom();
 
                                 break;
@@ -401,7 +457,6 @@ static int parse_argv(int argc, char *argv[]) {
 
                         FOREACH_WORD_SEPARATOR(word, length, optarg, ",", state) {
                                 _cleanup_free_ char *t;
-                                cap_value_t cap;
 
                                 t = strndup(word, length);
                                 if (!t)
@@ -413,7 +468,10 @@ static int parse_argv(int argc, char *argv[]) {
                                         else
                                                 minus = (uint64_t) -1;
                                 } else {
-                                        if (cap_from_name(t, &cap) < 0) {
+                                        int cap;
+
+                                        cap = capability_from_name(t);
+                                        if (cap < 0) {
                                                 log_error("Failed to parse capability %s.", t);
                                                 return -EINVAL;
                                         }
@@ -434,15 +492,19 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case ARG_LINK_JOURNAL:
-                        if (streq(optarg, "auto"))
+                        if (streq(optarg, "auto")) {
                                 arg_link_journal = LINK_AUTO;
-                        else if (streq(optarg, "no"))
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "no")) {
                                 arg_link_journal = LINK_NO;
-                        else if (streq(optarg, "guest"))
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "guest")) {
                                 arg_link_journal = LINK_GUEST;
-                        else if (streq(optarg, "host"))
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "host")) {
                                 arg_link_journal = LINK_HOST;
-                        else if (streq(optarg, "try-guest")) {
+                                arg_link_journal_try = false;
+                        } else if (streq(optarg, "try-guest")) {
                                 arg_link_journal = LINK_GUEST;
                                 arg_link_journal_try = true;
                         } else if (streq(optarg, "try-host")) {
@@ -595,6 +657,65 @@ static int parse_argv(int argc, char *argv[]) {
 
                         break;
 
+                case 'p': {
+                        const char *split, *e;
+                        uint16_t container_port, host_port;
+                        int protocol;
+                        ExposePort *p;
+
+                        if ((e = startswith(optarg, "tcp:")))
+                                protocol = IPPROTO_TCP;
+                        else if ((e = startswith(optarg, "udp:")))
+                                protocol = IPPROTO_UDP;
+                        else {
+                                e = optarg;
+                                protocol = IPPROTO_TCP;
+                        }
+
+                        split = strchr(e, ':');
+                        if (split) {
+                                char v[split - e + 1];
+
+                                memcpy(v, e, split - e);
+                                v[split - e] = 0;
+
+                                r = safe_atou16(v, &host_port);
+                                if (r < 0 || host_port <= 0) {
+                                        log_error("Failed to parse host port: %s", optarg);
+                                        return -EINVAL;
+                                }
+
+                                r = safe_atou16(split + 1, &container_port);
+                        } else {
+                                r = safe_atou16(e, &container_port);
+                                host_port = container_port;
+                        }
+
+                        if (r < 0 || container_port <= 0) {
+                                log_error("Failed to parse host port: %s", optarg);
+                                return -EINVAL;
+                        }
+
+                        LIST_FOREACH(ports, p, arg_expose_ports) {
+                                if (p->protocol == protocol && p->host_port == host_port) {
+                                        log_error("Duplicate port specification: %s", optarg);
+                                        return -EINVAL;
+                                }
+                        }
+
+                        p = new(ExposePort, 1);
+                        if (!p)
+                                return log_oom();
+
+                        p->protocol = protocol;
+                        p->host_port = host_port;
+                        p->container_port = container_port;
+
+                        LIST_PREPEND(ports, arg_expose_ports, p);
+
+                        break;
+                }
+
                 case '?':
                         return -EINVAL;
 
@@ -620,11 +741,41 @@ static int parse_argv(int argc, char *argv[]) {
                 return -EINVAL;
         }
 
+        if (arg_template && arg_image) {
+                log_error("--template= and --image= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_template && !(arg_directory || arg_machine)) {
+                log_error("--template= needs --directory= or --machine=.");
+                return -EINVAL;
+        }
+
+        if (arg_ephemeral && arg_template) {
+                log_error("--ephemeral and --template= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_ephemeral && arg_image) {
+                log_error("--ephemeral and --image= may not be combined.");
+                return -EINVAL;
+        }
+
+        if (arg_ephemeral && !IN_SET(arg_link_journal, LINK_NO, LINK_AUTO)) {
+                log_error("--ephemeral and --link-journal= may not be combined.");
+                return -EINVAL;
+        }
+
         if (arg_volatile != VOLATILE_NO && arg_read_only) {
                 log_error("Cannot combine --read-only with --volatile. Note that --volatile already implies a read-only base hierarchy.");
                 return -EINVAL;
         }
 
+        if (arg_expose_ports && !arg_private_network) {
+                log_error("Cannot use --port= without private networking.");
+                return -EINVAL;
+        }
+
         arg_retain = (arg_retain | plus | (arg_private_network ? 1ULL << CAP_NET_ADMIN : 0)) & ~minus;
 
         return 1;
@@ -796,6 +947,112 @@ static int mount_binds(const char *dest, char **l, bool ro) {
         return 0;
 }
 
+static int mount_cgroup_hierarchy(const char *dest, const char *controller, const char *hierarchy, bool read_only) {
+        char *to;
+        int r;
+
+        to = strappenda(dest, "/sys/fs/cgroup/", hierarchy);
+
+        r = path_is_mount_point(to, false);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine if %s is mounted already: %m", to);
+        if (r > 0)
+                return 0;
+
+        mkdir_p(to, 0755);
+
+        if (mount("cgroup", to, "cgroup", MS_NOSUID|MS_NOEXEC|MS_NODEV|(read_only ? MS_RDONLY : 0), controller) < 0)
+                return log_error_errno(errno, "Failed to mount to %s: %m", to);
+
+        return 1;
+}
+
+static int mount_cgroup(const char *dest) {
+        _cleanup_set_free_free_ Set *controllers = NULL;
+        _cleanup_free_ char *own_cgroup_path = NULL;
+        const char *cgroup_root, *systemd_root, *systemd_own;
+        int r;
+
+        controllers = set_new(&string_hash_ops);
+        if (!controllers)
+                return log_oom();
+
+        r = cg_kernel_controllers(controllers);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine cgroup controllers: %m");
+
+        r = cg_pid_get_path(NULL, 0, &own_cgroup_path);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine our own cgroup path: %m");
+
+        cgroup_root = strappenda(dest, "/sys/fs/cgroup");
+        if (mount("tmpfs", cgroup_root, "tmpfs", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, "mode=755") < 0)
+                return log_error_errno(errno, "Failed to mount tmpfs to /sys/fs/cgroup: %m");
+
+        for (;;) {
+                _cleanup_free_ char *controller = NULL, *origin = NULL, *combined = NULL;
+
+                controller = set_steal_first(controllers);
+                if (!controller)
+                        break;
+
+                origin = strappend("/sys/fs/cgroup/", controller);
+                if (!origin)
+                        return log_oom();
+
+                r = readlink_malloc(origin, &combined);
+                if (r == -EINVAL) {
+                        /* Not a symbolic link, but directly a single cgroup hierarchy */
+
+                        r = mount_cgroup_hierarchy(dest, controller, controller, true);
+                        if (r < 0)
+                                return r;
+
+                } else if (r < 0)
+                        return log_error_errno(r, "Failed to read link %s: %m", origin);
+                else {
+                        _cleanup_free_ char *target = NULL;
+
+                        target = strjoin(dest, "/sys/fs/cgroup/", controller, NULL);
+                        if (!target)
+                                return log_oom();
+
+                        /* A symbolic link, a combination of controllers in one hierarchy */
+
+                        if (!filename_is_valid(combined)) {
+                                log_warning("Ignoring invalid combined hierarchy %s.", combined);
+                                continue;
+                        }
+
+                        r = mount_cgroup_hierarchy(dest, combined, combined, true);
+                        if (r < 0)
+                                return r;
+
+                        if (symlink(combined, target) < 0)
+                                return log_error_errno(errno, "Failed to create symlink for combined hiearchy: %m");
+                }
+        }
+
+        r = mount_cgroup_hierarchy(dest, "name=systemd", "systemd", false);
+        if (r < 0)
+                return r;
+
+        /* Make our own cgroup a (writable) bind mount */
+        systemd_own = strappenda(dest, "/sys/fs/cgroup/systemd", own_cgroup_path);
+        if (mount(systemd_own, systemd_own,  NULL, MS_BIND, NULL) < 0)
+                return log_error_errno(errno, "Failed to turn %s into a bind mount: %m", own_cgroup_path);
+
+        /* And then remount the systemd cgroup root read-only */
+        systemd_root = strappenda(dest, "/sys/fs/cgroup/systemd");
+        if (mount(NULL, systemd_root, NULL, MS_BIND|MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_RDONLY, NULL) < 0)
+                return log_error_errno(errno, "Failed to mount cgroup root read-only: %m");
+
+        if (mount(NULL, cgroup_root, NULL, MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755") < 0)
+                return log_error_errno(errno, "Failed to remount %s read-only: %m", cgroup_root);
+
+        return 0;
+}
+
 static int mount_tmpfs(const char *dest) {
         char **i, **o;
 
@@ -808,8 +1065,8 @@ static int mount_tmpfs(const char *dest) {
                         return log_oom();
 
                 r = mkdir_label(where, 0755);
-                if (r < 0 && errno != EEXIST)
-                        return log_error_errno(r, "creating mount point for tmpfs %s failed: %m", where);
+                if (r < 0 && r != -EEXIST)
+                        return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where);
 
                 if (mount("tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, *o) < 0)
                         return log_error_errno(errno, "tmpfs mount to %s failed: %m", where);
@@ -913,7 +1170,7 @@ static int setup_resolv_conf(const char *dest) {
                 return 0;
         }
 
-        r = copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW, 0644);
+        r = copy_file("/etc/resolv.conf", where, O_TRUNC|O_NOFOLLOW, 0644, 0);
         if (r < 0) {
                 log_warning_errno(r, "Failed to copy /etc/resolv.conf to %s: %m", where);
 
@@ -1112,7 +1369,7 @@ static int copy_devnodes(const char *dest) {
                         }
 
                         if (mknod(to, st.st_mode, st.st_rdev) < 0)
-                                return log_error_errno(errno, "mknod(%s) failed: %m", dest);
+                                return log_error_errno(errno, "mknod(%s) failed: %m", to);
                 }
         }
 
@@ -1170,8 +1427,8 @@ static int setup_dev_console(const char *dest, const char *console) {
 
 static int setup_kmsg(const char *dest, int kmsg_socket) {
         _cleanup_free_ char *from = NULL, *to = NULL;
-        int r, fd, k;
         _cleanup_umask_ mode_t u;
+        int r, fd, k;
         union {
                 struct cmsghdr cmsghdr;
                 uint8_t buf[CMSG_SPACE(sizeof(int))];
@@ -1222,7 +1479,7 @@ static int setup_kmsg(const char *dest, int kmsg_socket) {
 
         /* Store away the fd in the socket, so that it stays open as
          * long as we run the child */
-        k = sendmsg(kmsg_socket, &mh, MSG_DONTWAIT|MSG_NOSIGNAL);
+        k = sendmsg(kmsg_socket, &mh, MSG_NOSIGNAL);
         safe_close(fd);
 
         if (k < 0)
@@ -1233,6 +1490,198 @@ static int setup_kmsg(const char *dest, int kmsg_socket) {
         return 0;
 }
 
+static int send_rtnl(int send_fd) {
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(int))];
+        } control = {};
+        struct msghdr mh = {
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+        };
+        struct cmsghdr *cmsg;
+        _cleanup_close_ int fd = -1;
+        ssize_t k;
+
+        assert(send_fd >= 0);
+
+        if (!arg_expose_ports)
+                return 0;
+
+        fd = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_ROUTE);
+        if (fd < 0)
+                return log_error_errno(errno, "failed to allocate container netlink: %m");
+
+        cmsg = CMSG_FIRSTHDR(&mh);
+        cmsg->cmsg_level = SOL_SOCKET;
+        cmsg->cmsg_type = SCM_RIGHTS;
+        cmsg->cmsg_len = CMSG_LEN(sizeof(int));
+        memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
+
+        mh.msg_controllen = cmsg->cmsg_len;
+
+        /* Store away the fd in the socket, so that it stays open as
+         * long as we run the child */
+        k = sendmsg(send_fd, &mh, MSG_NOSIGNAL);
+        if (k < 0)
+                return log_error_errno(errno, "Failed to send netlink fd: %m");
+
+        return 0;
+}
+
+static int flush_ports(union in_addr_union *exposed) {
+        ExposePort *p;
+        int r, af = AF_INET;
+
+        assert(exposed);
+
+        if (!arg_expose_ports)
+                return 0;
+
+        if (in_addr_is_null(af, exposed))
+                return 0;
+
+        log_debug("Lost IP address.");
+
+        LIST_FOREACH(ports, p, arg_expose_ports) {
+                r = fw_add_local_dnat(false,
+                                      af,
+                                      p->protocol,
+                                      NULL,
+                                      NULL, 0,
+                                      NULL, 0,
+                                      p->host_port,
+                                      exposed,
+                                      p->container_port,
+                                      NULL);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to modify firewall: %m");
+        }
+
+        *exposed = IN_ADDR_NULL;
+        return 0;
+}
+
+static int expose_ports(sd_rtnl *rtnl, union in_addr_union *exposed) {
+        _cleanup_free_ struct local_address *addresses = NULL;
+        _cleanup_free_ char *pretty = NULL;
+        union in_addr_union new_exposed;
+        ExposePort *p;
+        bool add;
+        int af = AF_INET, r;
+
+        assert(exposed);
+
+        /* Invoked each time an address is added or removed inside the
+         * container */
+
+        if (!arg_expose_ports)
+                return 0;
+
+        r = local_addresses(rtnl, 0, af, &addresses);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enumerate local addresses: %m");
+
+        add = r > 0 &&
+                addresses[0].family == af &&
+                addresses[0].scope < RT_SCOPE_LINK;
+
+        if (!add)
+                return flush_ports(exposed);
+
+        new_exposed = addresses[0].address;
+        if (in_addr_equal(af, exposed, &new_exposed))
+                return 0;
+
+        in_addr_to_string(af, &new_exposed, &pretty);
+        log_debug("New container IP is %s.", strna(pretty));
+
+        LIST_FOREACH(ports, p, arg_expose_ports) {
+
+                r = fw_add_local_dnat(true,
+                                      af,
+                                      p->protocol,
+                                      NULL,
+                                      NULL, 0,
+                                      NULL, 0,
+                                      p->host_port,
+                                      &new_exposed,
+                                      p->container_port,
+                                      in_addr_is_null(af, exposed) ? NULL : exposed);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to modify firewall: %m");
+        }
+
+        *exposed = new_exposed;
+        return 0;
+}
+
+static int on_address_change(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
+        union in_addr_union *exposed = userdata;
+
+        assert(rtnl);
+        assert(m);
+        assert(exposed);
+
+        expose_ports(rtnl, exposed);
+        return 0;
+}
+
+static int watch_rtnl(sd_event *event, int recv_fd, union in_addr_union *exposed, sd_rtnl **ret) {
+        union {
+                struct cmsghdr cmsghdr;
+                uint8_t buf[CMSG_SPACE(sizeof(int))];
+        } control = {};
+        struct msghdr mh = {
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+        };
+        struct cmsghdr *cmsg;
+        _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+        int fd, r;
+        ssize_t k;
+
+        assert(event);
+        assert(recv_fd >= 0);
+        assert(ret);
+
+        if (!arg_expose_ports)
+                return 0;
+
+        k = recvmsg(recv_fd, &mh, MSG_NOSIGNAL);
+        if (k < 0)
+                return log_error_errno(errno, "Failed to recv netlink fd: %m");
+
+        cmsg = CMSG_FIRSTHDR(&mh);
+        assert(cmsg->cmsg_level == SOL_SOCKET);
+        assert(cmsg->cmsg_type == SCM_RIGHTS);
+        assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int)));
+        memcpy(&fd, CMSG_DATA(cmsg), sizeof(int));
+
+        r = sd_rtnl_open_fd(&rtnl, fd, 1, RTNLGRP_IPV4_IFADDR);
+        if (r < 0) {
+                safe_close(fd);
+                return log_error_errno(r, "Failed to create rtnl object: %m");
+        }
+
+        r = sd_rtnl_add_match(rtnl, RTM_NEWADDR, on_address_change, exposed);
+        if (r < 0)
+                return log_error_errno(r, "Failed to subscribe to RTM_NEWADDR messages: %m");
+
+        r = sd_rtnl_add_match(rtnl, RTM_DELADDR, on_address_change, exposed);
+        if (r < 0)
+                return log_error_errno(r, "Failed to subscribe to RTM_DELADDR messages: %m");
+
+        r = sd_rtnl_attach_event(rtnl, event, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add to even loop: %m");
+
+        *ret = rtnl;
+        rtnl = NULL;
+
+        return 0;
+}
+
 static int setup_hostname(void) {
 
         if (arg_share_system)
@@ -1250,6 +1699,10 @@ static int setup_journal(const char *directory) {
         char *id;
         int r;
 
+        /* Don't link journals in ephemeral mode */
+        if (arg_ephemeral)
+                return 0;
+
         p = strappend(directory, "/etc/machine-id");
         if (!p)
                 return log_oom();
@@ -1278,8 +1731,7 @@ static int setup_journal(const char *directory) {
                          "Host and machine ids are equal (%s): refusing to link journals", id);
                 if (arg_link_journal == LINK_AUTO)
                         return 0;
-                return
-                        -EEXIST;
+                return -EEXIST;
         }
 
         if (arg_link_journal == LINK_NO)
@@ -1589,16 +2041,19 @@ static int reset_audit_loginuid(void) {
 
 #define HOST_HASH_KEY SD_ID128_MAKE(1a,37,6f,c7,46,ec,45,0b,ad,a3,d5,31,06,60,5d,b1)
 #define CONTAINER_HASH_KEY SD_ID128_MAKE(c3,c4,f9,19,b5,57,b2,1c,e6,cf,14,27,03,9c,ee,a2)
+#define MACVLAN_HASH_KEY SD_ID128_MAKE(00,13,6d,bc,66,83,44,81,bb,0c,f9,51,1f,24,a6,6f)
 
-static int generate_mac(struct ether_addr *mac, sd_id128_t hash_key) {
-        int r;
-
+static int generate_mac(struct ether_addr *mac, sd_id128_t hash_key, uint64_t idx) {
         uint8_t result[8];
         size_t l, sz;
-        uint8_t *v;
+        uint8_t *v, *i;
+        int r;
 
         l = strlen(arg_machine);
         sz = sizeof(sd_id128_t) + l;
+        if (idx > 0)
+                sz += sizeof(idx);
+
         v = alloca(sz);
 
         /* fetch some persistent data unique to the host */
@@ -1608,7 +2063,11 @@ static int generate_mac(struct ether_addr *mac, sd_id128_t hash_key) {
 
         /* combine with some data unique (on this host) to this
          * container instance */
-        memcpy(v + sizeof(sd_id128_t), arg_machine, l);
+        i = mempcpy(v + sizeof(sd_id128_t), arg_machine, l);
+        if (idx > 0) {
+                idx = htole64(idx);
+                memcpy(i, &idx, sizeof(idx));
+        }
 
         /* Let's hash the host machine ID plus the container name. We
          * use a fixed, but originally randomly created hash key here. */
@@ -1641,17 +2100,13 @@ static int setup_veth(pid_t pid, char iface_name[IFNAMSIZ], int *ifi) {
         snprintf(iface_name, IFNAMSIZ - 1, "%s-%s",
                  arg_network_bridge ? "vb" : "ve", arg_machine);
 
-        r = generate_mac(&mac_container, CONTAINER_HASH_KEY);
-        if (r < 0) {
-                log_error("Failed to generate predictable MAC address for container side");
-                return r;
-        }
+        r = generate_mac(&mac_container, CONTAINER_HASH_KEY, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate predictable MAC address for container side: %m");
 
-        r = generate_mac(&mac_host, HOST_HASH_KEY);
-        if (r < 0) {
-                log_error("Failed to generate predictable MAC address for host side");
-                return r;
-        }
+        r = generate_mac(&mac_host, HOST_HASH_KEY, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate predictable MAC address for host side: %m");
 
         r = sd_rtnl_open(&rtnl, 0);
         if (r < 0)
@@ -1836,6 +2291,7 @@ static int move_network_interfaces(pid_t pid) {
 static int setup_macvlan(pid_t pid) {
         _cleanup_udev_unref_ struct udev *udev = NULL;
         _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+        unsigned idx = 0;
         char **i;
         int r;
 
@@ -1858,12 +2314,17 @@ static int setup_macvlan(pid_t pid) {
         STRV_FOREACH(i, arg_network_macvlan) {
                 _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
                 _cleanup_free_ char *n = NULL;
+                struct ether_addr mac;
                 int ifi;
 
                 ifi = parse_interface(udev, *i);
                 if (ifi < 0)
                         return ifi;
 
+                r = generate_mac(&mac, MACVLAN_HASH_KEY, idx++);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to create MACVLAN MAC address: %m");
+
                 r = sd_rtnl_message_new_link(rtnl, &m, RTM_NEWLINK, 0);
                 if (r < 0)
                         return log_error_errno(r, "Failed to allocate netlink message: %m");
@@ -1882,6 +2343,10 @@ static int setup_macvlan(pid_t pid) {
                 if (r < 0)
                         return log_error_errno(r, "Failed to add netlink interface name: %m");
 
+                r = sd_rtnl_message_append_ether_addr(m, IFLA_ADDRESS, &mac);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add netlink MAC address: %m");
+
                 r = sd_rtnl_message_append_u32(m, IFLA_NET_NS_PID, pid);
                 if (r < 0)
                         return log_error_errno(r, "Failed to add netlink namespace field: %m");
@@ -1994,6 +2459,27 @@ finish:
 
 }
 
+static int setup_propagate(const char *root) {
+        const char *p, *q;
+
+        (void) mkdir_p("/run/systemd/nspawn/", 0755);
+        (void) mkdir_p("/run/systemd/nspawn/propagate", 0600);
+        p = strappenda("/run/systemd/nspawn/propagate/", arg_machine);
+        (void) mkdir_p(p, 0600);
+
+        q = strappenda(root, "/run/systemd/nspawn/incoming");
+        mkdir_parents(q, 0755);
+        mkdir_p(q, 0600);
+
+        if (mount(p, q, NULL, MS_BIND, NULL) < 0)
+                return log_error_errno(errno, "Failed to install propagation bind mount.");
+
+        if (mount(NULL, q, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0)
+                return log_error_errno(errno, "Failed to make propagation mount read-only");
+
+        return 0;
+}
+
 static int setup_image(char **device_path, int *loop_nr) {
         struct loop_info64 info = {
                 .lo_flags = LO_FLAGS_AUTOCLEAR|LO_FLAGS_PARTSCAN
@@ -2005,6 +2491,7 @@ static int setup_image(char **device_path, int *loop_nr) {
 
         assert(device_path);
         assert(loop_nr);
+        assert(arg_image);
 
         fd = open(arg_image, O_CLOEXEC|(arg_read_only ? O_RDONLY : O_RDWR)|O_NONBLOCK|O_NOCTTY);
         if (fd < 0)
@@ -2103,6 +2590,7 @@ static int dissect_image(
         assert(home_device);
         assert(srv_device);
         assert(secondary);
+        assert(arg_image);
 
         b = blkid_new_probe();
         if (!b)
@@ -2770,78 +3258,116 @@ static int on_orderly_shutdown(sd_event_source *s, const struct signalfd_siginfo
         return 0;
 }
 
-int main(int argc, char *argv[]) {
-
-        _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_device = NULL;
-        bool root_device_rw = true, home_device_rw = true, srv_device_rw = true;
-        _cleanup_close_ int master = -1, image_fd = -1;
-        _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 };
-        _cleanup_fdset_free_ FDSet *fds = NULL;
-        int r = EXIT_FAILURE, k, n_fd_passed, loop_nr = -1;
-        const char *console = NULL;
-        char veth_name[IFNAMSIZ];
-        bool secondary = false;
-        sigset_t mask, mask_chld;
-        pid_t pid = 0;
+static int determine_names(void) {
+        int r;
 
-        log_parse_environment();
-        log_open();
+        if (!arg_image && !arg_directory) {
+                if (arg_machine) {
+                        _cleanup_(image_unrefp) Image *i = NULL;
 
-        k = parse_argv(argc, argv);
-        if (k < 0)
-                goto finish;
-        else if (k == 0) {
-                r = EXIT_SUCCESS;
-                goto finish;
-        }
+                        r = image_find(arg_machine, &i);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to find image for machine '%s': %m", arg_machine);
+                        else if (r == 0) {
+                                log_error("No image for machine '%s': %m", arg_machine);
+                                return -ENOENT;
+                        }
 
-        if (!arg_image) {
-                if (arg_directory) {
-                        char *p;
+                        if (i->type == IMAGE_GPT)
+                                r = set_sanitized_path(&arg_image, i->path);
+                        else
+                                r = set_sanitized_path(&arg_directory, i->path);
+                        if (r < 0)
+                                return log_error_errno(r, "Invalid image directory: %m");
 
-                        p = path_make_absolute_cwd(arg_directory);
-                        free(arg_directory);
-                        arg_directory = p;
+                        arg_read_only = arg_read_only || i->read_only;
                 } else
                         arg_directory = get_current_dir_name();
 
-                if (!arg_directory) {
-                        log_error("Failed to determine path, please use -D.");
-                        goto finish;
+                if (!arg_directory && !arg_machine) {
+                        log_error("Failed to determine path, please use -D or -i.");
+                        return -EINVAL;
                 }
-                path_kill_slashes(arg_directory);
         }
 
         if (!arg_machine) {
-                arg_machine = strdup(basename(arg_image ? arg_image : arg_directory));
-                if (!arg_machine) {
-                        log_oom();
-                        goto finish;
-                }
+                if (arg_directory && path_equal(arg_directory, "/"))
+                        arg_machine = gethostname_malloc();
+                else
+                        arg_machine = strdup(basename(arg_image ?: arg_directory));
+
+                if (!arg_machine)
+                        return log_oom();
 
                 hostname_cleanup(arg_machine, false);
-                if (isempty(arg_machine)) {
+                if (!machine_name_is_valid(arg_machine)) {
                         log_error("Failed to determine machine name automatically, please use -M.");
-                        goto finish;
+                        return -EINVAL;
+                }
+
+                if (arg_ephemeral) {
+                        char *b;
+
+                        /* Add a random suffix when this is an
+                         * ephemeral machine, so that we can run many
+                         * instances at once without manually having
+                         * to specify -M each time. */
+
+                        if (asprintf(&b, "%s-%016" PRIx64, arg_machine, random_u64()) < 0)
+                                return log_oom();
+
+                        free(arg_machine);
+                        arg_machine = b;
                 }
         }
 
+        return 0;
+}
+
+int main(int argc, char *argv[]) {
+
+        _cleanup_free_ char *device_path = NULL, *root_device = NULL, *home_device = NULL, *srv_device = NULL, *console = NULL;
+        bool root_device_rw = true, home_device_rw = true, srv_device_rw = true;
+        _cleanup_close_ int master = -1, image_fd = -1;
+        _cleanup_fdset_free_ FDSet *fds = NULL;
+        int r, n_fd_passed, loop_nr = -1;
+        char veth_name[IFNAMSIZ];
+        bool secondary = false, remove_subvol = false;
+        sigset_t mask, mask_chld;
+        pid_t pid = 0;
+        int ret = EXIT_SUCCESS;
+        union in_addr_union exposed = {};
+        _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                goto finish;
+
+        r = determine_names();
+        if (r < 0)
+                goto finish;
+
         if (geteuid() != 0) {
                 log_error("Need to be root.");
+                r = -EPERM;
                 goto finish;
         }
 
         if (sd_booted() <= 0) {
                 log_error("Not running on a systemd system.");
+                r = -EINVAL;
                 goto finish;
         }
 
         log_close();
         n_fd_passed = sd_listen_fds(false);
         if (n_fd_passed > 0) {
-                k = fdset_new_listen_fds(&fds, false);
-                if (k < 0) {
-                        log_error_errno(k, "Failed to collect file descriptors: %m");
+                r = fdset_new_listen_fds(&fds, false);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to collect file descriptors: %m");
                         goto finish;
                 }
         }
@@ -2849,14 +3375,86 @@ int main(int argc, char *argv[]) {
         log_open();
 
         if (arg_directory) {
-                if (path_equal(arg_directory, "/")) {
-                        log_error("Spawning container on root directory not supported.");
+                assert(!arg_image);
+
+                if (path_equal(arg_directory, "/") && !arg_ephemeral) {
+                        log_error("Spawning container on root directory is not supported. Consider using --ephemeral.");
+                        r = -EINVAL;
                         goto finish;
                 }
 
+                if (arg_ephemeral) {
+                        _cleanup_release_lock_file_ LockFile original_lock = LOCK_FILE_INIT;
+                        char *np;
+
+                        /* If the specified path is a mount point we
+                         * generate the new snapshot immediately
+                         * inside it under a random name. However if
+                         * the specified is not a mount point we
+                         * create the new snapshot in the parent
+                         * directory, just next to it. */
+                        r = path_is_mount_point(arg_directory, false);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to determine whether directory %s is mount point: %m", arg_directory);
+                                goto finish;
+                        }
+                        if (r > 0)
+                                r = tempfn_random_child(arg_directory, &np);
+                        else
+                                r = tempfn_random(arg_directory, &np);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to generate name for snapshot: %m");
+                                goto finish;
+                        }
+
+                        r = image_path_lock(np, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to lock %s: %m", np);
+                                goto finish;
+                        }
+
+                        r = btrfs_subvol_snapshot(arg_directory, np, arg_read_only, true);
+                        if (r < 0) {
+                                free(np);
+                                log_error_errno(r, "Failed to create snapshot %s from %s: %m", np, arg_directory);
+                                goto finish;
+                        }
+
+                        free(arg_directory);
+                        arg_directory = np;
+
+                        remove_subvol = true;
+
+                } else {
+                        r = image_path_lock(arg_directory, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                        if (r == -EBUSY) {
+                                log_error_errno(r, "Directory tree %s is currently busy.", arg_directory);
+                                goto finish;
+                        }
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to lock %s: %m", arg_directory);
+                                return r;
+                        }
+
+                        if (arg_template) {
+                                r = btrfs_subvol_snapshot(arg_template, arg_directory, arg_read_only, true);
+                                if (r == -EEXIST) {
+                                        if (!arg_quiet)
+                                                log_info("Directory %s already exists, not populating from template %s.", arg_directory, arg_template);
+                                } else if (r < 0) {
+                                        log_error_errno(r, "Couldn't create snapshort %s from %s: %m", arg_directory, arg_template);
+                                        goto finish;
+                                } else {
+                                        if (!arg_quiet)
+                                                log_info("Populated %s from template %s.", arg_directory, arg_template);
+                                }
+                        }
+                }
+
                 if (arg_boot) {
                         if (path_is_os_tree(arg_directory) <= 0) {
                                 log_error("Directory %s doesn't look like an OS root directory (os-release file is missing). Refusing.", arg_directory);
+                                r = -EINVAL;
                                 goto finish;
                         }
                 } else {
@@ -2866,13 +3464,27 @@ int main(int argc, char *argv[]) {
                                        argc > optind && path_is_absolute(argv[optind]) ? argv[optind] : "/usr/bin/");
                         if (access(p, F_OK) < 0) {
                                 log_error("Directory %s lacks the binary to execute or doesn't look like a binary tree. Refusing.", arg_directory);
+                                r = -EINVAL;
                                 goto finish;
-
                         }
                 }
+
         } else {
                 char template[] = "/tmp/nspawn-root-XXXXXX";
 
+                assert(arg_image);
+                assert(!arg_template);
+
+                r = image_path_lock(arg_image, (arg_read_only ? LOCK_SH : LOCK_EX) | LOCK_NB, &tree_global_lock, &tree_local_lock);
+                if (r == -EBUSY) {
+                        r = log_error_errno(r, "Disk image %s is currently busy.", arg_image);
+                        goto finish;
+                }
+                if (r < 0) {
+                        r = log_error_errno(r, "Failed to create image lock: %m");
+                        goto finish;
+                }
+
                 if (!mkdtemp(template)) {
                         log_error_errno(errno, "Failed to create temporary directory: %m");
                         r = -errno;
@@ -2902,34 +3514,25 @@ int main(int argc, char *argv[]) {
 
         master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);
         if (master < 0) {
-                log_error_errno(errno, "Failed to acquire pseudo tty: %m");
+                r = log_error_errno(errno, "Failed to acquire pseudo tty: %m");
                 goto finish;
         }
 
-        console = ptsname(master);
-        if (!console) {
-                log_error_errno(errno, "Failed to determine tty name: %m");
+        r = ptsname_malloc(master, &console);
+        if (r < 0) {
+                r = log_error_errno(r, "Failed to determine tty name: %m");
                 goto finish;
         }
 
         if (!arg_quiet)
                 log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",
-                         arg_machine, arg_image ? arg_image : arg_directory);
+                         arg_machine, arg_image ?: arg_directory);
 
         if (unlockpt(master) < 0) {
-                log_error_errno(errno, "Failed to unlock tty: %m");
+                r = log_error_errno(errno, "Failed to unlock tty: %m");
                 goto finish;
         }
 
-        if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
-                log_error_errno(errno, "Failed to create kmsg socket pair: %m");
-                goto finish;
-        }
-
-        sd_notify(false,
-                  "READY=1\n"
-                  "STATUS=Container running.");
-
         assert_se(sigemptyset(&mask) == 0);
         sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);
         assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
@@ -2938,6 +3541,7 @@ int main(int argc, char *argv[]) {
         assert_se(sigaddset(&mask_chld, SIGCHLD) == 0);
 
         for (;;) {
+                _cleanup_close_pair_ int kmsg_socket_pair[2] = { -1, -1 }, rtnl_socket_pair[2] = { -1, -1 };
                 ContainerStatus container_status;
                 _cleanup_(barrier_destroy) Barrier barrier = BARRIER_NULL;
                 struct sigaction sa = {
@@ -2951,31 +3555,40 @@ int main(int argc, char *argv[]) {
                         goto finish;
                 }
 
+                if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, kmsg_socket_pair) < 0) {
+                        r = log_error_errno(errno, "Failed to create kmsg socket pair: %m");
+                        goto finish;
+                }
+
+                if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, rtnl_socket_pair) < 0) {
+                        r = log_error_errno(errno, "Failed to create rtnl socket pair: %m");
+                        goto finish;
+                }
+
                 /* Child can be killed before execv(), so handle SIGCHLD
                  * in order to interrupt parent's blocking calls and
                  * give it a chance to call wait() and terminate. */
                 r = sigprocmask(SIG_UNBLOCK, &mask_chld, NULL);
                 if (r < 0) {
-                        log_error_errno(errno, "Failed to change the signal mask: %m");
+                        r = log_error_errno(errno, "Failed to change the signal mask: %m");
                         goto finish;
                 }
 
                 r = sigaction(SIGCHLD, &sa, NULL);
                 if (r < 0) {
-                        log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
+                        r = log_error_errno(errno, "Failed to install SIGCHLD handler: %m");
                         goto finish;
                 }
 
-                pid = syscall(__NR_clone, SIGCHLD|CLONE_NEWNS|
-                                          (arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS)|
-                                          (arg_private_network ? CLONE_NEWNET : 0), NULL);
+                pid = raw_clone(SIGCHLD|CLONE_NEWNS|
+                                (arg_share_system ? 0 : CLONE_NEWIPC|CLONE_NEWPID|CLONE_NEWUTS)|
+                                (arg_private_network ? CLONE_NEWNET : 0), NULL);
                 if (pid < 0) {
                         if (errno == EINVAL)
-                                log_error_errno(errno, "clone() failed, do you have namespace support enabled in your kernel? (You need UTS, IPC, PID and NET namespacing built in): %m");
+                                r = log_error_errno(errno, "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_errno(errno, "clone() failed: %m");
+                                r = log_error_errno(errno, "clone() failed: %m");
 
-                        r = pid;
                         goto finish;
                 }
 
@@ -3010,18 +3623,19 @@ int main(int argc, char *argv[]) {
                         close_nointr(STDERR_FILENO);
 
                         kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);
+                        rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
 
                         reset_all_signal_handlers();
                         reset_signal_mask();
 
-                        k = open_terminal(console, O_RDWR);
-                        if (k != STDIN_FILENO) {
-                                if (k >= 0) {
-                                        safe_close(k);
-                                        k = -EINVAL;
+                        r = open_terminal(console, O_RDWR);
+                        if (r != STDIN_FILENO) {
+                                if (r >= 0) {
+                                        safe_close(r);
+                                        r = -EINVAL;
                                 }
 
-                                log_error_errno(k, "Failed to open console: %m");
+                                log_error_errno(r, "Failed to open console: %m");
                                 _exit(EXIT_FAILURE);
                         }
 
@@ -3076,9 +3690,9 @@ int main(int argc, char *argv[]) {
                                 _exit(EXIT_FAILURE);
 
                         if (arg_read_only) {
-                                k = bind_remount_recursive(arg_directory, true);
-                                if (k < 0) {
-                                        log_error_errno(k, "Failed to make tree read-only: %m");
+                                r = bind_remount_recursive(arg_directory, true);
+                                if (r < 0) {
+                                        log_error_errno(r, "Failed to make tree read-only: %m");
                                         _exit(EXIT_FAILURE);
                                 }
                         }
@@ -3094,6 +3708,9 @@ int main(int argc, char *argv[]) {
 
                         dev_setup(arg_directory);
 
+                        if (setup_propagate(arg_directory) < 0)
+                                _exit(EXIT_FAILURE);
+
                         if (setup_seccomp() < 0)
                                 _exit(EXIT_FAILURE);
 
@@ -3102,9 +3719,17 @@ int main(int argc, char *argv[]) {
 
                         if (setup_kmsg(arg_directory, kmsg_socket_pair[1]) < 0)
                                 _exit(EXIT_FAILURE);
-
                         kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
 
+                        if (send_rtnl(rtnl_socket_pair[1]) < 0)
+                                _exit(EXIT_FAILURE);
+                        rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
+
+                        /* Tell the parent that we are ready, and that
+                         * it can cgroupify us to that we lack access
+                         * to certain devices and resources. */
+                        (void) barrier_place(&barrier);
+
                         if (setup_boot_id(arg_directory) < 0)
                                 _exit(EXIT_FAILURE);
 
@@ -3126,10 +3751,12 @@ int main(int argc, char *argv[]) {
                         if (mount_tmpfs(arg_directory) < 0)
                                 _exit(EXIT_FAILURE);
 
-                        /* Tell the parent that we are ready, and that
-                         * it can cgroupify us to that we lack access
-                         * to certain devices and resources. */
-                        (void)barrier_place(&barrier);
+                        /* Wait until we are cgroup-ified, so that we
+                         * can mount the right cgroup path writable */
+                        (void) barrier_sync_next(&barrier);
+
+                        if (mount_cgroup(arg_directory) < 0)
+                                _exit(EXIT_FAILURE);
 
                         if (chdir(arg_directory) < 0) {
                                 log_error_errno(errno, "chdir(%s) failed: %m", arg_directory);
@@ -3182,9 +3809,9 @@ int main(int argc, char *argv[]) {
                         }
 
                         if (fdset_size(fds) > 0) {
-                                k = fdset_cloexec(fds, false);
-                                if (k < 0) {
-                                        log_error("Failed to unset O_CLOEXEC for file descriptors.");
+                                r = fdset_cloexec(fds, false);
+                                if (r < 0) {
+                                        log_error_errno(r, "Failed to unset O_CLOEXEC for file descriptors.");
                                         _exit(EXIT_FAILURE);
                                 }
 
@@ -3268,10 +3895,13 @@ int main(int argc, char *argv[]) {
                 fdset_free(fds);
                 fds = NULL;
 
-                /* wait for child-setup to be done */
-                if (barrier_place_and_sync(&barrier)) {
-                        _cleanup_event_unref_ sd_event *event = NULL;
-                        _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
+                kmsg_socket_pair[1] = safe_close(kmsg_socket_pair[1]);
+                rtnl_socket_pair[1] = safe_close(rtnl_socket_pair[1]);
+
+                /* Wait for the most basic Child-setup to be done,
+                 * before we add hardware to it, and place it in a
+                 * cgroup. */
+                if (barrier_sync_next(&barrier)) {
                         int ifi = 0;
 
                         r = move_network_interfaces(pid);
@@ -3308,44 +3938,71 @@ int main(int argc, char *argv[]) {
                         /* Notify the child that the parent is ready with all
                          * its setup, and that the child can now hand over
                          * control to the code to run inside the container. */
-                        (void)barrier_place(&barrier);
+                        (void) barrier_place(&barrier);
 
-                        r = sd_event_new(&event);
-                        if (r < 0) {
-                                log_error_errno(r, "Failed to get default event source: %m");
-                                goto finish;
-                        }
+                        /* And wait that the child is completely ready now. */
+                        if (barrier_place_and_sync(&barrier)) {
+                                _cleanup_event_unref_ sd_event *event = NULL;
+                                _cleanup_(pty_forward_freep) PTYForward *forward = NULL;
+                                _cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
+                                char last_char = 0;
 
-                        if (arg_boot) {
-                                /* Try to kill the init system on SIGINT or SIGTERM */
-                                sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, UINT32_TO_PTR(pid));
-                                sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, UINT32_TO_PTR(pid));
-                        } else {
-                                /* Immediately exit */
-                                sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
-                                sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
-                        }
+                                sd_notifyf(false,
+                                           "READY=1\n"
+                                           "STATUS=Container running.\n"
+                                           "X_NSPAWN_LEADER_PID=" PID_FMT, pid);
 
-                        /* simply exit on sigchld */
-                        sd_event_add_signal(event, NULL, SIGCHLD, NULL, NULL);
+                                r = sd_event_new(&event);
+                                if (r < 0) {
+                                        log_error_errno(r, "Failed to get default event source: %m");
+                                        goto finish;
+                                }
 
-                        r = pty_forward_new(event, master, &forward);
-                        if (r < 0) {
-                                log_error_errno(r, "Failed to create PTY forwarder: %m");
-                                goto finish;
-                        }
+                                if (arg_boot) {
+                                        /* Try to kill the init system on SIGINT or SIGTERM */
+                                        sd_event_add_signal(event, NULL, SIGINT, on_orderly_shutdown, UINT32_TO_PTR(pid));
+                                        sd_event_add_signal(event, NULL, SIGTERM, on_orderly_shutdown, UINT32_TO_PTR(pid));
+                                } else {
+                                        /* Immediately exit */
+                                        sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);
+                                        sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);
+                                }
 
-                        r = sd_event_loop(event);
-                        if (r < 0)
-                                return log_error_errno(r, "Failed to run event loop: %m");
+                                /* simply exit on sigchld */
+                                sd_event_add_signal(event, NULL, SIGCHLD, NULL, NULL);
 
-                        forward = pty_forward_free(forward);
+                                if (arg_expose_ports) {
+                                        r = watch_rtnl(event, rtnl_socket_pair[0], &exposed, &rtnl);
+                                        if (r < 0)
+                                                goto finish;
 
-                        if (!arg_quiet)
-                                putc('\n', stdout);
+                                        (void) expose_ports(rtnl, &exposed);
+                                }
+
+                                rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);
 
-                        /* Kill if it is not dead yet anyway */
-                        terminate_machine(pid);
+                                r = pty_forward_new(event, master, true, &forward);
+                                if (r < 0) {
+                                        log_error_errno(r, "Failed to create PTY forwarder: %m");
+                                        goto finish;
+                                }
+
+                                r = sd_event_loop(event);
+                                if (r < 0) {
+                                        log_error_errno(r, "Failed to run event loop: %m");
+                                        goto finish;
+                                }
+
+                                pty_forward_get_last_char(forward, &last_char);
+
+                                forward = pty_forward_free(forward);
+
+                                if (!arg_quiet && last_char != '\n')
+                                        putc('\n', stdout);
+
+                                /* Kill if it is not dead yet anyway */
+                                terminate_machine(pid);
+                        }
                 }
 
                 /* Normally redundant, but better safe than sorry */
@@ -3354,16 +4011,17 @@ int main(int argc, char *argv[]) {
                 r = wait_for_container(pid, &container_status);
                 pid = 0;
 
-                if (r < 0) {
+                if (r < 0)
                         /* We failed to wait for the container, or the
                          * container exited abnormally */
-                        r = EXIT_FAILURE;
-                        break;
-                } else if (r > 0 || container_status == CONTAINER_TERMINATED)
+                        goto finish;
+                else if (r > 0 || container_status == CONTAINER_TERMINATED){
                         /* The container exited with a non-zero
                          * status, or with zero status and no reboot
                          * was requested. */
+                        ret = r;
                         break;
+                }
 
                 /* CONTAINER_REBOOTED, loop again */
 
@@ -3378,9 +4036,12 @@ int main(int argc, char *argv[]) {
                          * restart. This is necessary since we might
                          * have cgroup parameters set we want to have
                          * flushed out. */
-                        r = 133;
+                        ret = 133;
+                        r = 0;
                         break;
                 }
+
+                flush_ports(&exposed);
         }
 
 finish:
@@ -3393,7 +4054,24 @@ finish:
         if (pid > 0)
                 kill(pid, SIGKILL);
 
+        if (remove_subvol && arg_directory) {
+                int k;
+
+                k = btrfs_subvol_remove(arg_directory);
+                if (k < 0)
+                        log_warning_errno(k, "Cannot remove subvolume '%s', ignoring: %m", arg_directory);
+        }
+
+        if (arg_machine) {
+                const char *p;
+
+                p = strappenda("/run/systemd/nspawn/propagate/", arg_machine);
+                (void) rm_rf(p, false, true, false);
+        }
+
         free(arg_directory);
+        free(arg_template);
+        free(arg_image);
         free(arg_machine);
         free(arg_user);
         strv_free(arg_setenv);
@@ -3403,5 +4081,13 @@ finish:
         strv_free(arg_bind_ro);
         strv_free(arg_tmpfs);
 
-        return r;
+        flush_ports(&exposed);
+
+        while (arg_expose_ports) {
+                ExposePort *p = arg_expose_ports;
+                LIST_REMOVE(ports, arg_expose_ports, p);
+                free(p);
+        }
+
+        return r < 0 ? EXIT_FAILURE : ret;
 }