machined: introduce pseudo-machine ".host" refererring to the host system

Some of the operations machined/machinectl implement are also very
useful when applied to the host system (such as machinectl login,
machinectl shell or machinectl status), hence introduce a pseudo-machine
by the name of ".host" in machined that refers to the host system, and
may be used top execute operations on the host system with.

This copies the pseudo-image ".host" machined already implements for
image related commands.

(This commit also adds a PK privilege for opening a PTY in a container,
which was previously not accessible for non-root.)

8 files changed, 367 insertions, 188 deletions

diff --git a/src/machine/machine-dbus.c b/src/machine/machine-dbus.c
index ad3dd8facf..b89bb2cba1 100644
--- a/src/machine/machine-dbus.c
+++ b/src/machine/machine-dbus.c
@@ -186,141 +186,179 @@ int bus_machine_method_kill(sd_bus_message *message, void *userdata, sd_bus_erro
 
 int bus_machine_method_get_addresses(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
-        _cleanup_close_pair_ int pair[2] = { -1, -1 };
-        _cleanup_free_ char *us = NULL, *them = NULL;
-        _cleanup_close_ int netns_fd = -1;
         Machine *m = userdata;
-        const char *p;
-        siginfo_t si;
-        pid_t child;
         int r;
 
         assert(message);
         assert(m);
 
-        if (m->class != MACHINE_CONTAINER)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Requesting IP address data is only supported on container machines.");
-
-        r = readlink_malloc("/proc/self/ns/net", &us);
-        if (r < 0)
-                return r;
-
-        p = procfs_file_alloca(m->leader, "ns/net");
-        r = readlink_malloc(p, &them);
+        r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
                 return r;
 
-        if (streq(us, them))
-                return sd_bus_error_setf(error, BUS_ERROR_NO_PRIVATE_NETWORKING, "Machine %s does not use private networking", m->name);
-
-        r = namespace_open(m->leader, NULL, NULL, &netns_fd, NULL, NULL);
+        r = sd_bus_message_open_container(reply, 'a', "(iay)");
         if (r < 0)
                 return r;
 
-        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
-                return -errno;
-
-        child = fork();
-        if (child < 0)
-                return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
+        switch (m->class) {
 
-        if (child == 0) {
+        case MACHINE_HOST: {
                 _cleanup_free_ struct local_address *addresses = NULL;
                 struct local_address *a;
-                int i, n;
-
-                pair[0] = safe_close(pair[0]);
-
-                r = namespace_enter(-1, -1, netns_fd, -1, -1);
-                if (r < 0)
-                        _exit(EXIT_FAILURE);
+                int n, i;
 
                 n = local_addresses(NULL, 0, AF_UNSPEC, &addresses);
                 if (n < 0)
-                        _exit(EXIT_FAILURE);
+                        return n;
 
                 for (a = addresses, i = 0; i < n; a++, i++) {
-                        struct iovec iov[2] = {
-                                { .iov_base = &a->family, .iov_len = sizeof(a->family) },
-                                { .iov_base = &a->address, .iov_len = FAMILY_ADDRESS_SIZE(a->family) },
-                        };
 
-                        r = writev(pair[1], iov, 2);
+                        r = sd_bus_message_open_container(reply, 'r', "iay");
                         if (r < 0)
-                                _exit(EXIT_FAILURE);
-                }
-
-                pair[1] = safe_close(pair[1]);
+                                return r;
 
-                _exit(EXIT_SUCCESS);
-        }
-
-        pair[1] = safe_close(pair[1]);
+                        r = sd_bus_message_append(reply, "i", addresses[i].family);
+                        if (r < 0)
+                                return r;
 
-        r = sd_bus_message_new_method_return(message, &reply);
-        if (r < 0)
-                return r;
+                        r = sd_bus_message_append_array(reply, 'y', &addresses[i].address, FAMILY_ADDRESS_SIZE(addresses[i].family));
+                        if (r < 0)
+                                return r;
 
-        r = sd_bus_message_open_container(reply, 'a', "(iay)");
-        if (r < 0)
-                return r;
+                        r = sd_bus_message_close_container(reply);
+                        if (r < 0)
+                                return r;
+                }
 
-        for (;;) {
-                int family;
-                ssize_t n;
-                union in_addr_union in_addr;
-                struct iovec iov[2];
-                struct msghdr mh = {
-                        .msg_iov = iov,
-                        .msg_iovlen = 2,
-                };
+                break;
+        }
 
-                iov[0] = (struct iovec) { .iov_base = &family, .iov_len = sizeof(family) };
-                iov[1] = (struct iovec) { .iov_base = &in_addr, .iov_len = sizeof(in_addr) };
+        case MACHINE_CONTAINER: {
+                _cleanup_close_pair_ int pair[2] = { -1, -1 };
+                _cleanup_free_ char *us = NULL, *them = NULL;
+                _cleanup_close_ int netns_fd = -1;
+                const char *p;
+                siginfo_t si;
+                pid_t child;
 
-                n = recvmsg(pair[0], &mh, 0);
-                if (n < 0)
-                        return -errno;
-                if ((size_t) n < sizeof(family))
-                        break;
+                r = readlink_malloc("/proc/self/ns/net", &us);
+                if (r < 0)
+                        return r;
 
-                r = sd_bus_message_open_container(reply, 'r', "iay");
+                p = procfs_file_alloca(m->leader, "ns/net");
+                r = readlink_malloc(p, &them);
                 if (r < 0)
                         return r;
 
-                r = sd_bus_message_append(reply, "i", family);
+                if (streq(us, them))
+                        return sd_bus_error_setf(error, BUS_ERROR_NO_PRIVATE_NETWORKING, "Machine %s does not use private networking", m->name);
+
+                r = namespace_open(m->leader, NULL, NULL, &netns_fd, NULL, NULL);
                 if (r < 0)
                         return r;
 
-                switch (family) {
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
+                        return -errno;
+
+                child = fork();
+                if (child < 0)
+                        return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
+
+                if (child == 0) {
+                        _cleanup_free_ struct local_address *addresses = NULL;
+                        struct local_address *a;
+                        int i, n;
+
+                        pair[0] = safe_close(pair[0]);
+
+                        r = namespace_enter(-1, -1, netns_fd, -1, -1);
+                        if (r < 0)
+                                _exit(EXIT_FAILURE);
 
-                case AF_INET:
-                        if (n != sizeof(struct in_addr) + sizeof(family))
-                                return -EIO;
+                        n = local_addresses(NULL, 0, AF_UNSPEC, &addresses);
+                        if (n < 0)
+                                _exit(EXIT_FAILURE);
 
-                        r = sd_bus_message_append_array(reply, 'y', &in_addr.in, sizeof(in_addr.in));
-                        break;
+                        for (a = addresses, i = 0; i < n; a++, i++) {
+                                struct iovec iov[2] = {
+                                        { .iov_base = &a->family, .iov_len = sizeof(a->family) },
+                                        { .iov_base = &a->address, .iov_len = FAMILY_ADDRESS_SIZE(a->family) },
+                                };
 
-                case AF_INET6:
-                        if (n != sizeof(struct in6_addr) + sizeof(family))
-                                return -EIO;
+                                r = writev(pair[1], iov, 2);
+                                if (r < 0)
+                                        _exit(EXIT_FAILURE);
+                        }
 
-                        r = sd_bus_message_append_array(reply, 'y', &in_addr.in6, sizeof(in_addr.in6));
-                        break;
+                        pair[1] = safe_close(pair[1]);
+
+                        _exit(EXIT_SUCCESS);
                 }
-                if (r < 0)
-                        return r;
 
-                r = sd_bus_message_close_container(reply);
+                pair[1] = safe_close(pair[1]);
+
+                for (;;) {
+                        int family;
+                        ssize_t n;
+                        union in_addr_union in_addr;
+                        struct iovec iov[2];
+                        struct msghdr mh = {
+                                .msg_iov = iov,
+                                .msg_iovlen = 2,
+                        };
+
+                        iov[0] = (struct iovec) { .iov_base = &family, .iov_len = sizeof(family) };
+                        iov[1] = (struct iovec) { .iov_base = &in_addr, .iov_len = sizeof(in_addr) };
+
+                        n = recvmsg(pair[0], &mh, 0);
+                        if (n < 0)
+                                return -errno;
+                        if ((size_t) n < sizeof(family))
+                                break;
+
+                        r = sd_bus_message_open_container(reply, 'r', "iay");
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_append(reply, "i", family);
+                        if (r < 0)
+                                return r;
+
+                        switch (family) {
+
+                        case AF_INET:
+                                if (n != sizeof(struct in_addr) + sizeof(family))
+                                        return -EIO;
+
+                                r = sd_bus_message_append_array(reply, 'y', &in_addr.in, sizeof(in_addr.in));
+                                break;
+
+                        case AF_INET6:
+                                if (n != sizeof(struct in6_addr) + sizeof(family))
+                                        return -EIO;
+
+                                r = sd_bus_message_append_array(reply, 'y', &in_addr.in6, sizeof(in_addr.in6));
+                                break;
+                        }
+                        if (r < 0)
+                                return r;
+
+                        r = sd_bus_message_close_container(reply);
+                        if (r < 0)
+                                return r;
+                }
+
+                r = wait_for_terminate(child, &si);
                 if (r < 0)
-                        return r;
+                        return sd_bus_error_set_errnof(error, r, "Failed to wait for client: %m");
+                if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Client died abnormally.");
+                break;
         }
 
-        r = wait_for_terminate(child, &si);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to wait for client: %m");
-        if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Client died abnormally.");
+        default:
+                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Requesting IP address data is only supported on container machines.");
+        }
 
         r = sd_bus_message_close_container(reply);
         if (r < 0)
@@ -331,73 +369,88 @@ int bus_machine_method_get_addresses(sd_bus_message *message, void *userdata, sd
 
 int bus_machine_method_get_os_release(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
-        _cleanup_close_ int mntns_fd = -1, root_fd = -1;
-        _cleanup_close_pair_ int pair[2] = { -1, -1 };
         _cleanup_strv_free_ char **l = NULL;
-        _cleanup_fclose_ FILE *f = NULL;
         Machine *m = userdata;
         char **k, **v;
-        siginfo_t si;
-        pid_t child;
         int r;
 
         assert(message);
         assert(m);
 
-        if (m->class != MACHINE_CONTAINER)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Requesting OS release data is only supported on container machines.");
+        switch (m->class) {
 
-        r = namespace_open(m->leader, NULL, &mntns_fd, NULL, NULL, &root_fd);
-        if (r < 0)
-                return r;
+        case MACHINE_HOST:
+                r = load_env_file_pairs(NULL, "/etc/os-release", NULL, &l);
+                if (r < 0)
+                        return r;
 
-        if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
-                return -errno;
+                break;
 
-        child = fork();
-        if (child < 0)
-                return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
+        case MACHINE_CONTAINER: {
+                _cleanup_close_ int mntns_fd = -1, root_fd = -1;
+                _cleanup_close_pair_ int pair[2] = { -1, -1 };
+                _cleanup_fclose_ FILE *f = NULL;
+                siginfo_t si;
+                pid_t child;
 
-        if (child == 0) {
-                _cleanup_close_ int fd = -1;
+                r = namespace_open(m->leader, NULL, &mntns_fd, NULL, NULL, &root_fd);
+                if (r < 0)
+                        return r;
 
-                pair[0] = safe_close(pair[0]);
+                if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
+                        return -errno;
 
-                r = namespace_enter(-1, mntns_fd, -1, -1, root_fd);
-                if (r < 0)
-                        _exit(EXIT_FAILURE);
+                child = fork();
+                if (child < 0)
+                        return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
+
+                if (child == 0) {
+                        _cleanup_close_ int fd = -1;
+
+                        pair[0] = safe_close(pair[0]);
+
+                        r = namespace_enter(-1, mntns_fd, -1, -1, root_fd);
+                        if (r < 0)
+                                _exit(EXIT_FAILURE);
+
+                        fd = open("/etc/os-release", O_RDONLY|O_CLOEXEC);
+                        if (fd < 0) {
+                                fd = open("/usr/lib/os-release", O_RDONLY|O_CLOEXEC);
+                                if (fd < 0)
+                                        _exit(EXIT_FAILURE);
+                        }
 
-                fd = open("/etc/os-release", O_RDONLY|O_CLOEXEC);
-                if (fd < 0) {
-                        fd = open("/usr/lib/os-release", O_RDONLY|O_CLOEXEC);
-                        if (fd < 0)
+                        r = copy_bytes(fd, pair[1], (off_t) -1, false);
+                        if (r < 0)
                                 _exit(EXIT_FAILURE);
+
+                        _exit(EXIT_SUCCESS);
                 }
 
-                r = copy_bytes(fd, pair[1], (off_t) -1, false);
-                if (r < 0)
-                        _exit(EXIT_FAILURE);
+                pair[1] = safe_close(pair[1]);
 
-                _exit(EXIT_SUCCESS);
-        }
+                f = fdopen(pair[0], "re");
+                if (!f)
+                        return -errno;
 
-        pair[1] = safe_close(pair[1]);
+                pair[0] = -1;
 
-        f = fdopen(pair[0], "re");
-        if (!f)
-                return -errno;
+                r = load_env_file_pairs(f, "/etc/os-release", NULL, &l);
+                if (r < 0)
+                        return r;
 
-        pair[0] = -1;
+                r = wait_for_terminate(child, &si);
+                if (r < 0)
+                        return sd_bus_error_set_errnof(error, r, "Failed to wait for client: %m");
+                if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Client died abnormally.");
 
-        r = load_env_file_pairs(f, "/etc/os-release", NULL, &l);
-        if (r < 0)
-                return r;
+                break;
+        }
 
-        r = wait_for_terminate(child, &si);
-        if (r < 0)
-                return sd_bus_error_set_errnof(error, r, "Failed to wait for client: %m");
-        if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Client died abnormally.");
+        default:
+                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Requesting OS release data is only supported on container machines.");
+        }
 
         r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
@@ -430,10 +483,20 @@ int bus_machine_method_open_pty(sd_bus_message *message, void *userdata, sd_bus_
         assert(message);
         assert(m);
 
-        if (m->class != MACHINE_CONTAINER)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Opening pseudo TTYs is only supported on container machines.");
+        r = bus_verify_polkit_async(
+                        message,
+                        CAP_SYS_ADMIN,
+                        "org.freedesktop.machine1.open-pty",
+                        false,
+                        UID_INVALID,
+                        &m->manager->polkit_registry,
+                        error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
 
-        master = openpt_in_namespace(m->leader, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        master = machine_openpt(m, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (master < 0)
                 return master;
 
@@ -453,31 +516,45 @@ int bus_machine_method_open_pty(sd_bus_message *message, void *userdata, sd_bus_
 }
 
 static int container_bus_new(Machine *m, sd_bus **ret) {
-        _cleanup_bus_unref_ sd_bus *bus = NULL;
-        char *address;
         int r;
 
         assert(m);
         assert(ret);
 
-        r = sd_bus_new(&bus);
-        if (r < 0)
-                return r;
+        switch (m->class) {
 
-        if (asprintf(&address, "x-machine-kernel:pid=%1$" PID_PRI ";x-machine-unix:pid=%1$" PID_PRI, m->leader) < 0)
-                return -ENOMEM;
+        case MACHINE_HOST:
+                *ret = NULL;
+                break;
 
-        bus->address = address;
-        bus->bus_client = true;
-        bus->trusted = false;
-        bus->is_system = true;
+        case MACHINE_CONTAINER: {
+                _cleanup_bus_unref_ sd_bus *bus = NULL;
+                char *address;
 
-        r = sd_bus_start(bus);
-        if (r < 0)
-                return r;
+                r = sd_bus_new(&bus);
+                if (r < 0)
+                        return r;
 
-        *ret = bus;
-        bus = NULL;
+                if (asprintf(&address, "x-machine-kernel:pid=%1$" PID_PRI ";x-machine-unix:pid=%1$" PID_PRI, m->leader) < 0)
+                        return -ENOMEM;
+
+                bus->address = address;
+                bus->bus_client = true;
+                bus->trusted = false;
+                bus->is_system = true;
+
+                r = sd_bus_start(bus);
+                if (r < 0)
+                        return r;
+
+                *ret = bus;
+                bus = NULL;
+                break;
+        }
+
+        default:
+                return -EOPNOTSUPP;
+        }
 
         return 0;
 }
@@ -485,8 +562,9 @@ static int container_bus_new(Machine *m, sd_bus **ret) {
 int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         _cleanup_free_ char *pty_name = NULL;
-        _cleanup_bus_unref_ sd_bus *container_bus = NULL;
+        _cleanup_bus_flush_close_unref_ sd_bus *allocated_bus = NULL;
         _cleanup_close_ int master = -1;
+        sd_bus *container_bus = NULL;
         Machine *m = userdata;
         const char *p, *getty;
         int r;
@@ -494,9 +572,6 @@ int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bu
         assert(message);
         assert(m);
 
-        if (m->class != MACHINE_CONTAINER)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Opening logins is only supported on container machines.");
-
         r = bus_verify_polkit_async(
                         message,
                         CAP_SYS_ADMIN,
@@ -510,7 +585,7 @@ int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bu
         if (r == 0)
                 return 1; /* Will call us back */
 
-        master = openpt_in_namespace(m->leader, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        master = machine_openpt(m, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (master < 0)
                 return master;
 
@@ -525,10 +600,12 @@ int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bu
         if (unlockpt(master) < 0)
                 return -errno;
 
-        r = container_bus_new(m, &container_bus);
+        r = container_bus_new(m, &allocated_bus);
         if (r < 0)
                 return r;
 
+        container_bus = allocated_bus ?: m->manager->bus;
+
         getty = strjoina("container-getty@", p, ".service");
 
         r = sd_bus_call_method(
@@ -542,8 +619,6 @@ int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bu
         if (r < 0)
                 return r;
 
-        container_bus = sd_bus_unref(container_bus);
-
         r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
                 return r;
@@ -558,7 +633,8 @@ int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bu
 int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL, *tm = NULL;
         _cleanup_free_ char *pty_name = NULL;
-        _cleanup_bus_unref_ sd_bus *container_bus = NULL;
+        _cleanup_bus_flush_close_unref_ sd_bus *allocated_bus = NULL;
+        sd_bus *container_bus = NULL;
         _cleanup_close_ int master = -1;
         _cleanup_strv_free_ char **env = NULL, **args = NULL;
         Machine *m = userdata;
@@ -597,9 +673,6 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
         if (!strv_env_is_valid(env))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid environment assignments");
 
-        if (m->class != MACHINE_CONTAINER)
-                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Opening shells is only supported on container machines.");
-
         r = bus_verify_polkit_async(
                         message,
                         CAP_SYS_ADMIN,
@@ -613,7 +686,7 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
         if (r == 0)
                 return 1; /* Will call us back */
 
-        master = openpt_in_namespace(m->leader, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        master = machine_openpt(m, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (master < 0)
                 return master;
 
@@ -631,10 +704,12 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
         if (unlockpt(master) < 0)
                 return -errno;
 
-        r = container_bus_new(m, &container_bus);
+        r = container_bus_new(m, &allocated_bus);
         if (r < 0)
                 return r;
 
+        container_bus = allocated_bus ?: m->manager->bus;
+
         r = sd_bus_message_new_method_call(
                         container_bus,
                         &tm,
@@ -645,9 +720,8 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
         if (r < 0)
                 return r;
 
-        unit = strjoina("container-shell@", p, ".service", NULL);
-
         /* Name and mode */
+        unit = strjoina("container-shell@", p, ".service", NULL);
         r = sd_bus_message_append(tm, "ss", unit, "fail");
         if (r < 0)
                 return r;
@@ -768,8 +842,6 @@ int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bu
         if (r < 0)
                 return r;
 
-        container_bus = sd_bus_unref(container_bus);
-
         r = sd_bus_message_new_method_return(message, &reply);
         if (r < 0)
                 return r;
@@ -1207,7 +1279,7 @@ const sd_bus_vtable machine_vtable[] = {
         SD_BUS_METHOD("Kill", "si", NULL, bus_machine_method_kill, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("GetAddresses", NULL, "a(iay)", bus_machine_method_get_addresses, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("GetOSRelease", NULL, "a{ss}", bus_machine_method_get_os_release, SD_BUS_VTABLE_UNPRIVILEGED),
-        SD_BUS_METHOD("OpenPTY", NULL, "hs", bus_machine_method_open_pty, 0),
+        SD_BUS_METHOD("OpenPTY", NULL, "hs", bus_machine_method_open_pty, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("OpenLogin", NULL, "hs", bus_machine_method_open_login, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("OpenShell", "ssasas", "hs", bus_machine_method_open_shell, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("BindMount", "ssbb", NULL, bus_machine_method_bind_mount, SD_BUS_VTABLE_UNPRIVILEGED),
diff --git a/src/machine/machine.c b/src/machine/machine.c
index f045159d41..0d1b119dc1 100644
--- a/src/machine/machine.c
+++ b/src/machine/machine.c
@@ -37,12 +37,17 @@
 #include "machine-dbus.h"
 #include "formats-util.h"
 
-Machine* machine_new(Manager *manager, const char *name) {
+Machine* machine_new(Manager *manager, MachineClass class, const char *name) {
         Machine *m;
 
         assert(manager);
+        assert(class < _MACHINE_CLASS_MAX);
         assert(name);
 
+        /* Passing class == _MACHINE_CLASS_INVALID here is fine. It
+         * means as much as "we don't know yet", and that we'll figure
+         * it out later when loading the state file. */
+
         m = new0(Machine, 1);
         if (!m)
                 return NULL;
@@ -51,14 +56,17 @@ Machine* machine_new(Manager *manager, const char *name) {
         if (!m->name)
                 goto fail;
 
-        m->state_file = strappend("/run/systemd/machines/", m->name);
-        if (!m->state_file)
-                goto fail;
+        if (class != MACHINE_HOST) {
+                m->state_file = strappend("/run/systemd/machines/", m->name);
+                if (!m->state_file)
+                        goto fail;
+        }
+
+        m->class = class;
 
         if (hashmap_put(manager->machines, m->name, m) < 0)
                 goto fail;
 
-        m->class = _MACHINE_CLASS_INVALID;
         m->manager = manager;
 
         return m;
@@ -86,6 +94,9 @@ void machine_free(Machine *m) {
 
         (void) hashmap_remove(m->manager->machines, m->name);
 
+        if (m->manager->host_machine == m)
+                m->manager->host_machine = NULL;
+
         if (m->leader > 0)
                 (void) hashmap_remove_value(m->manager->machine_leaders, UINT_TO_PTR(m->leader), m);
 
@@ -105,7 +116,9 @@ int machine_save(Machine *m) {
         int r;
 
         assert(m);
-        assert(m->state_file);
+
+        if (!m->state_file)
+                return 0;
 
         if (!m->started)
                 return 0;
@@ -244,6 +257,9 @@ int machine_load(Machine *m) {
 
         assert(m);
 
+        if (!m->state_file)
+                return 0;
+
         r = parse_env_file(m->state_file, NEWLINE,
                            "SCOPE",     &m->unit,
                            "SCOPE_JOB", &m->scope_job,
@@ -325,6 +341,7 @@ static int machine_start_scope(Machine *m, sd_bus_message *properties, sd_bus_er
         int r = 0;
 
         assert(m);
+        assert(m->class != MACHINE_HOST);
 
         if (!m->unit) {
                 _cleanup_free_ char *escaped = NULL;
@@ -364,6 +381,9 @@ int machine_start(Machine *m, sd_bus_message *properties, sd_bus_error *error) {
 
         assert(m);
 
+        if (!IN_SET(m->class, MACHINE_CONTAINER, MACHINE_VM))
+                return -EOPNOTSUPP;
+
         if (m->started)
                 return 0;
 
@@ -402,6 +422,7 @@ static int machine_stop_scope(Machine *m) {
         int r;
 
         assert(m);
+        assert(m->class != MACHINE_HOST);
 
         if (!m->unit)
                 return 0;
@@ -422,6 +443,9 @@ int machine_stop(Machine *m) {
         int r;
         assert(m);
 
+        if (!IN_SET(m->class, MACHINE_CONTAINER, MACHINE_VM))
+                return -EOPNOTSUPP;
+
         r = machine_stop_scope(m);
 
         m->stopping = true;
@@ -456,6 +480,9 @@ int machine_finalize(Machine *m) {
 bool machine_check_gc(Machine *m, bool drop_not_started) {
         assert(m);
 
+        if (m->class == MACHINE_HOST)
+                return true;
+
         if (drop_not_started && !m->started)
                 return false;
 
@@ -481,6 +508,9 @@ void machine_add_to_gc_queue(Machine *m) {
 MachineState machine_get_state(Machine *s) {
         assert(s);
 
+        if (s->class == MACHINE_HOST)
+                return MACHINE_RUNNING;
+
         if (s->stopping)
                 return MACHINE_CLOSING;
 
@@ -493,6 +523,9 @@ MachineState machine_get_state(Machine *s) {
 int machine_kill(Machine *m, KillWho who, int signo) {
         assert(m);
 
+        if (!IN_SET(m->class, MACHINE_VM, MACHINE_CONTAINER))
+                return -EOPNOTSUPP;
+
         if (!m->unit)
                 return -ESRCH;
 
@@ -509,6 +542,25 @@ int machine_kill(Machine *m, KillWho who, int signo) {
         return manager_kill_unit(m->manager, m->unit, signo, NULL);
 }
 
+int machine_openpt(Machine *m, int flags) {
+        assert(m);
+
+        switch (m->class) {
+
+        case MACHINE_HOST:
+                return posix_openpt(flags);
+
+        case MACHINE_CONTAINER:
+                if (m->leader <= 0)
+                        return -EINVAL;
+
+                return openpt_in_namespace(m->leader, flags);
+
+        default:
+                return -EOPNOTSUPP;
+        }
+}
+
 MachineOperation *machine_operation_unref(MachineOperation *o) {
         if (!o)
                 return NULL;
@@ -544,7 +596,8 @@ void machine_release_unit(Machine *m) {
 
 static const char* const machine_class_table[_MACHINE_CLASS_MAX] = {
         [MACHINE_CONTAINER] = "container",
-        [MACHINE_VM] = "vm"
+        [MACHINE_VM] = "vm",
+        [MACHINE_HOST] = "host",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(machine_class, MachineClass);
diff --git a/src/machine/machine.h b/src/machine/machine.h
index 0132b65a97..5f978289f2 100644
--- a/src/machine/machine.h
+++ b/src/machine/machine.h
@@ -39,6 +39,7 @@ typedef enum MachineState {
 typedef enum MachineClass {
         MACHINE_CONTAINER,
         MACHINE_VM,
+        MACHINE_HOST,
         _MACHINE_CLASS_MAX,
         _MACHINE_CLASS_INVALID = -1
 } MachineClass;
@@ -95,7 +96,7 @@ struct Machine {
         unsigned n_operations;
 };
 
-Machine* machine_new(Manager *manager, const char *name);
+Machine* machine_new(Manager *manager, MachineClass class, const char *name);
 void machine_free(Machine *m);
 bool machine_check_gc(Machine *m, bool drop_not_started);
 void machine_add_to_gc_queue(Machine *m);
@@ -120,3 +121,5 @@ MachineState machine_state_from_string(const char *s) _pure_;
 
 const char *kill_who_to_string(KillWho k) _const_;
 KillWho kill_who_from_string(const char *s) _pure_;
+
+int machine_openpt(Machine *m, int flags);
diff --git a/src/machine/machinectl.c b/src/machine/machinectl.c
index 72b9a619d2..c84deba1c0 100644
--- a/src/machine/machinectl.c
+++ b/src/machine/machinectl.c
@@ -358,7 +358,8 @@ static int show_unit_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
                         bus,
                         "org.freedesktop.systemd1",
                         path,
-                        endswith(unit, ".scope") ? "org.freedesktop.systemd1.Scope" : "org.freedesktop.systemd1.Service",
+                        endswith(unit, ".scope") ? "org.freedesktop.systemd1.Scope" :
+                        endswith(unit, ".slice") ? "org.freedesktop.systemd1.Slice" : "org.freedesktop.systemd1.Service",
                         "ControlGroup",
                         &error,
                         &reply,
@@ -372,9 +373,6 @@ static int show_unit_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
         if (r < 0)
                 return bus_log_parse_error(r);
 
-        if (isempty(cgroup))
-                return 0;
-
         if (cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, cgroup, false) != 0 && leader <= 0)
                 return 0;
 
diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index 03625ba4cd..29649899ed 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -1508,7 +1508,7 @@ int manager_add_machine(Manager *m, const char *name, Machine **_machine) {
 
         machine = hashmap_get(m->machines, name);
         if (!machine) {
-                machine = machine_new(m, name);
+                machine = machine_new(m, _MACHINE_CLASS_INVALID, name);
                 if (!machine)
                         return -ENOMEM;
         }
diff --git a/src/machine/machined.c b/src/machine/machined.c
index 9b9a334838..df3cc9972a 100644
--- a/src/machine/machined.c
+++ b/src/machine/machined.c
@@ -90,6 +90,45 @@ void manager_free(Manager *m) {
         free(m);
 }
 
+static int manager_add_host_machine(Manager *m) {
+        _cleanup_free_ char *rd = NULL, *unit = NULL;
+        sd_id128_t mid;
+        Machine *t;
+        int r;
+
+        if (m->host_machine)
+                return 0;
+
+        r = sd_id128_get_machine(&mid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to get machine ID: %m");
+
+        rd = strdup("/");
+        if (!rd)
+                return log_oom();
+
+        unit = strdup("-.slice");
+        if (!unit)
+                return log_oom();
+
+        t = machine_new(m, MACHINE_HOST, ".host");
+        if (!t)
+                return log_oom();
+
+        t->leader = 1;
+        t->id = mid;
+
+        t->root_directory = rd;
+        t->unit = unit;
+        rd = unit = NULL;
+
+        dual_timestamp_from_boottime_or_monotonic(&t->timestamp, 0);
+
+        m->host_machine = t;
+
+        return 0;
+}
+
 int manager_enumerate_machines(Manager *m) {
         _cleanup_closedir_ DIR *d = NULL;
         struct dirent *de;
@@ -97,6 +136,10 @@ int manager_enumerate_machines(Manager *m) {
 
         assert(m);
 
+        r = manager_add_host_machine(m);
+        if (r < 0)
+                return r;
+
         /* Read in machine data stored on disk */
         d = opendir("/run/systemd/machines");
         if (!d) {
@@ -123,9 +166,7 @@ int manager_enumerate_machines(Manager *m) {
 
                 k = manager_add_machine(m, de->d_name, &machine);
                 if (k < 0) {
-                        log_error_errno(k, "Failed to add machine by file name %s: %m", de->d_name);
-
-                        r = k;
+                        r = log_error_errno(k, "Failed to add machine by file name %s: %m", de->d_name);
                         continue;
                 }
 
diff --git a/src/machine/machined.h b/src/machine/machined.h
index 61dbefb5f1..b3e59bf998 100644
--- a/src/machine/machined.h
+++ b/src/machine/machined.h
@@ -48,6 +48,8 @@ struct Manager {
         sd_event_source *image_cache_defer_event;
 
         LIST_HEAD(Machine, machine_gc_queue);
+
+        Machine *host_machine;
 };
 
 Manager *manager_new(void);
diff --git a/src/machine/org.freedesktop.machine1.policy.in b/src/machine/org.freedesktop.machine1.policy.in
index b3b2fa29c1..f1557806d1 100644
--- a/src/machine/org.freedesktop.machine1.policy.in
+++ b/src/machine/org.freedesktop.machine1.policy.in
@@ -26,6 +26,16 @@
                 </defaults>
         </action>
 
+        <action id="org.freedesktop.machine1.open-pty">
+                <_description>Acquire a pseudo TTY in a local container</_description>
+                <_message>Authentication is acquire a pseudo TTY in a local container.</_message>
+                <defaults>
+                        <allow_any>auth_admin</allow_any>
+                        <allow_inactive>auth_admin</allow_inactive>
+                        <allow_active>auth_admin_keep</allow_active>
+                </defaults>
+        </action>
+
         <action id="org.freedesktop.machine1.shell">
                 <_description>Acquire a shell in a local container</_description>
                 <_message>Authentication is required to acquire a shell in a local container.</_message>