/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <errno.h>
#include <sys/mount.h>
#include <sys/wait.h>

/* When we include libgen.h because we need dirname() we immediately
 * undefine basename() since libgen.h defines it as a macro to the POSIX
 * version which is really broken. We prefer GNU basename(). */
#include <libgen.h>
#undef basename

#include "alloc-util.h"
#include "bus-common-errors.h"
#include "bus-get-properties.h"
#include "bus-internal.h"
#include "bus-label.h"
#include "bus-locator.h"
#include "bus-polkit.h"
#include "copy.h"
#include "env-file.h"
#include "env-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
#include "fs-util.h"
#include "in-addr-util.h"
#include "io-util.h"
#include "local-addresses.h"
#include "machine-dbus.h"
#include "machine.h"
#include "missing_capability.h"
#include "mkdir.h"
#include "mount-util.h"
#include "mountpoint-util.h"
#include "namespace-util.h"
#include "os-util.h"
#include "path-util.h"
#include "process-util.h"
#include "signal-util.h"
#include "strv.h"
#include "terminal-util.h"
#include "tmpfile-util.h"
#include "user-util.h"

static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_class, machine_class, MachineClass);
static BUS_DEFINE_PROPERTY_GET2(property_get_state, "s", Machine, machine_get_state, machine_state_to_string);

static int property_get_netif(
                sd_bus *bus,
                const char *path,
                const char *interface,
                const char *property,
                sd_bus_message *reply,
                void *userdata,
                sd_bus_error *error) {

        Machine *m = userdata;

        assert(bus);
        assert(reply);
        assert(m);

        assert_cc(sizeof(int) == sizeof(int32_t));

        return sd_bus_message_append_array(reply, 'i', m->netif, m->n_netif * sizeof(int));
}

int bus_machine_method_unregister(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        Machine *m = userdata;
        int r;

        assert(message);
        assert(m);

        r = bus_verify_polkit_async(
                        message,
                        CAP_KILL,
                        "org.freedesktop.machine1.manage-machines",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        r = machine_finalize(m);
        if (r < 0)
                return r;

        return sd_bus_reply_method_return(message, NULL);
}

int bus_machine_method_terminate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        Machine *m = userdata;
        int r;

        assert(message);
        assert(m);

        r = bus_verify_polkit_async(
                        message,
                        CAP_KILL,
                        "org.freedesktop.machine1.manage-machines",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        r = machine_stop(m);
        if (r < 0)
                return r;

        return sd_bus_reply_method_return(message, NULL);
}

int bus_machine_method_kill(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        Machine *m = userdata;
        const char *swho;
        int32_t signo;
        KillWho who;
        int r;

        assert(message);
        assert(m);

        r = sd_bus_message_read(message, "si", &swho, &signo);
        if (r < 0)
                return r;

        if (isempty(swho))
                who = KILL_ALL;
        else {
                who = kill_who_from_string(swho);
                if (who < 0)
                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid kill parameter '%s'", swho);
        }

        if (!SIGNAL_VALID(signo))
                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid signal %i", signo);

        r = bus_verify_polkit_async(
                        message,
                        CAP_KILL,
                        "org.freedesktop.machine1.manage-machines",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        r = machine_kill(m, who, signo);
        if (r < 0)
                return r;

        return sd_bus_reply_method_return(message, NULL);
}

int bus_machine_method_get_addresses(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
        Machine *m = userdata;
        int r;

        assert(message);
        assert(m);

        r = sd_bus_message_new_method_return(message, &reply);
        if (r < 0)
                return r;

        r = sd_bus_message_open_container(reply, 'a', "(iay)");
        if (r < 0)
                return r;

        switch (m->class) {

        case MACHINE_HOST: {
                _cleanup_free_ struct local_address *addresses = NULL;
                struct local_address *a;
                int n, i;

                n = local_addresses(NULL, 0, AF_UNSPEC, &addresses);
                if (n < 0)
                        return n;

                for (a = addresses, i = 0; i < n; a++, i++) {

                        r = sd_bus_message_open_container(reply, 'r', "iay");
                        if (r < 0)
                                return r;

                        r = sd_bus_message_append(reply, "i", addresses[i].family);
                        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_close_container(reply);
                        if (r < 0)
                                return r;
                }

                break;
        }

        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;
                pid_t child;

                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);
                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);
                if (r < 0)
                        return r;

                if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
                        return -errno;

                r = namespace_fork("(sd-addrns)", "(sd-addr)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG,
                                   -1, -1, netns_fd, -1, -1, &child);
                if (r < 0)
                        return sd_bus_error_set_errnof(error, r, "Failed to fork(): %m");
                if (r == 0) {
                        _cleanup_free_ struct local_address *addresses = NULL;
                        struct local_address *a;
                        int i, n;

                        pair[0] = safe_close(pair[0]);

                        n = local_addresses(NULL, 0, AF_UNSPEC, &addresses);
                        if (n < 0)
                                _exit(EXIT_FAILURE);

                        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);
                                if (r < 0)
                                        _exit(EXIT_FAILURE);
                        }

                        pair[1] = safe_close(pair[1]);

                        _exit(EXIT_SUCCESS);
                }

                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] = IOVEC_MAKE(&family, sizeof(family));
                        iov[1] = IOVEC_MAKE(&in_addr, 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_and_check("(sd-addrns)", child, 0);
                if (r < 0)
                        return sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m");
                if (r != EXIT_SUCCESS)
                        return sd_bus_error_set(error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
                break;
        }

        default:
                return sd_bus_error_set(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)
                return r;

        return sd_bus_send(NULL, reply, NULL);
}

#define EXIT_NOT_FOUND 2

int bus_machine_method_get_os_release(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        _cleanup_strv_free_ char **l = NULL;
        Machine *m = userdata;
        int r;

        assert(message);
        assert(m);

        switch (m->class) {

        case MACHINE_HOST:
                r = load_os_release_pairs(NULL, &l);
                if (r < 0)
                        return r;

                break;

        case MACHINE_CONTAINER: {
                _cleanup_close_ int mntns_fd = -1, root_fd = -1, pidns_fd = -1;
                _cleanup_close_pair_ int pair[2] = { -1, -1 };
                _cleanup_fclose_ FILE *f = NULL;
                pid_t child;

                r = namespace_open(m->leader, &pidns_fd, &mntns_fd, NULL, NULL, &root_fd);
                if (r < 0)
                        return r;

                if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
                        return -errno;

                r = namespace_fork("(sd-osrelns)", "(sd-osrel)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG,
                                   pidns_fd, mntns_fd, -1, -1, root_fd,
                                   &child);
                if (r < 0)
                        return sd_bus_error_set_errnof(error, r, "Failed to fork(): %m");
                if (r == 0) {
                        int fd = -1;

                        pair[0] = safe_close(pair[0]);

                        r = open_os_release(NULL, NULL, &fd);
                        if (r == -ENOENT)
                                _exit(EXIT_NOT_FOUND);
                        if (r < 0)
                                _exit(EXIT_FAILURE);

                        r = copy_bytes(fd, pair[1], UINT64_MAX, 0);
                        if (r < 0)
                                _exit(EXIT_FAILURE);

                        _exit(EXIT_SUCCESS);
                }

                pair[1] = safe_close(pair[1]);

                f = take_fdopen(&pair[0], "r");
                if (!f)
                        return -errno;

                r = load_env_file_pairs(f, "/etc/os-release", &l);
                if (r < 0)
                        return r;

                r = wait_for_terminate_and_check("(sd-osrelns)", child, 0);
                if (r < 0)
                        return sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m");
                if (r == EXIT_NOT_FOUND)
                        return sd_bus_error_set(error, SD_BUS_ERROR_FAILED, "Machine does not contain OS release information");
                if (r != EXIT_SUCCESS)
                        return sd_bus_error_set(error, SD_BUS_ERROR_FAILED, "Child died abnormally.");

                break;
        }

        default:
                return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Requesting OS release data is only supported on container machines.");
        }

        return bus_reply_pair_array(message, l);
}

int bus_machine_method_open_pty(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
        _cleanup_free_ char *pty_name = NULL;
        _cleanup_close_ int master = -1;
        Machine *m = userdata;
        int r;

        assert(message);
        assert(m);

        r = bus_verify_polkit_async(
                        message,
                        CAP_SYS_ADMIN,
                        m->class == MACHINE_HOST ? "org.freedesktop.machine1.host-open-pty" : "org.freedesktop.machine1.open-pty",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        master = machine_openpt(m, O_RDWR|O_NOCTTY|O_CLOEXEC, &pty_name);
        if (master < 0)
                return master;

        r = sd_bus_message_new_method_return(message, &reply);
        if (r < 0)
                return r;

        r = sd_bus_message_append(reply, "hs", master, pty_name);
        if (r < 0)
                return r;

        return sd_bus_send(NULL, reply, NULL);
}

static int container_bus_new(Machine *m, sd_bus_error *error, sd_bus **ret) {
        int r;

        assert(m);
        assert(ret);

        switch (m->class) {

        case MACHINE_HOST:
                *ret = NULL;
                break;

        case MACHINE_CONTAINER: {
                _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL;
                char *address;

                r = sd_bus_new(&bus);
                if (r < 0)
                        return r;

                if (asprintf(&address, "x-machine-unix:pid=%" 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 == -ENOENT)
                        return sd_bus_error_set_errnof(error, r, "There is no system bus in container %s.", m->name);
                if (r < 0)
                        return r;

                *ret = TAKE_PTR(bus);
                break;
        }

        default:
                return -EOPNOTSUPP;
        }

        return 0;
}

int bus_machine_method_open_login(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
        _cleanup_free_ char *pty_name = NULL;
        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *allocated_bus = NULL;
        _cleanup_close_ int master = -1;
        sd_bus *container_bus = NULL;
        Machine *m = userdata;
        const char *p, *getty;
        int r;

        assert(message);
        assert(m);

        r = bus_verify_polkit_async(
                        message,
                        CAP_SYS_ADMIN,
                        m->class == MACHINE_HOST ? "org.freedesktop.machine1.host-login" : "org.freedesktop.machine1.login",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        master = machine_openpt(m, O_RDWR|O_NOCTTY|O_CLOEXEC, &pty_name);
        if (master < 0)
                return master;

        p = path_startswith(pty_name, "/dev/pts/");
        assert(p);

        r = container_bus_new(m, error, &allocated_bus);
        if (r < 0)
                return r;

        container_bus = allocated_bus ?: m->manager->bus;

        getty = strjoina("container-getty@", p, ".service");

        r = bus_call_method(container_bus, bus_systemd_mgr, "StartUnit", error, NULL, "ss", getty, "replace");
        if (r < 0)
                return r;

        r = sd_bus_message_new_method_return(message, &reply);
        if (r < 0)
                return r;

        r = sd_bus_message_append(reply, "hs", master, pty_name);
        if (r < 0)
                return r;

        return sd_bus_send(NULL, reply, NULL);
}

int bus_machine_method_open_shell(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL, *tm = NULL;
        _cleanup_free_ char *pty_name = NULL;
        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *allocated_bus = NULL;
        sd_bus *container_bus = NULL;
        _cleanup_close_ int master = -1, slave = -1;
        _cleanup_strv_free_ char **env = NULL, **args_wire = NULL, **args = NULL;
        Machine *m = userdata;
        const char *p, *unit, *user, *path, *description, *utmp_id;
        int r;

        assert(message);
        assert(m);

        r = sd_bus_message_read(message, "ss", &user, &path);
        if (r < 0)
                return r;
        user = isempty(user) ? "root" : user;
        r = sd_bus_message_read_strv(message, &args_wire);
        if (r < 0)
                return r;
        if (isempty(path)) {
                path = "/bin/sh";

                args = new0(char*, 3 + 1);
                if (!args)
                        return -ENOMEM;
                args[0] = strdup("sh");
                if (!args[0])
                        return -ENOMEM;
                args[1] = strdup("-c");
                if (!args[1])
                        return -ENOMEM;
                r = asprintf(&args[2],
                             "shell=$(getent passwd %s 2>/dev/null | { IFS=: read _ _ _ _ _ _ x; echo \"$x\"; })\n"\
                             "exec \"${shell:-/bin/sh}\" -l", /* -l is means --login */
                             user);
                if (r < 0) {
                        args[2] = NULL;
                        return -ENOMEM;
                }
        } else {
                if (!path_is_absolute(path))
                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Specified path '%s' is not absolute", path);
                args = TAKE_PTR(args_wire);
                if (strv_isempty(args)) {
                        args = strv_free(args);

                        args = strv_new(path);
                        if (!args)
                                return -ENOMEM;
                }
        }

        r = sd_bus_message_read_strv(message, &env);
        if (r < 0)
                return r;
        if (!strv_env_is_valid(env))
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid environment assignments");

        const char *details[] = {
                "machine", m->name,
                "user", user,
                "program", path,
                NULL
        };

        r = bus_verify_polkit_async(
                        message,
                        CAP_SYS_ADMIN,
                        m->class == MACHINE_HOST ? "org.freedesktop.machine1.host-shell" : "org.freedesktop.machine1.shell",
                        details,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        master = machine_openpt(m, O_RDWR|O_NOCTTY|O_CLOEXEC, &pty_name);
        if (master < 0)
                return master;

        p = path_startswith(pty_name, "/dev/pts/");
        assert(p);

        slave = machine_open_terminal(m, pty_name, O_RDWR|O_NOCTTY|O_CLOEXEC);
        if (slave < 0)
                return slave;

        utmp_id = path_startswith(pty_name, "/dev/");
        assert(utmp_id);

        r = container_bus_new(m, error, &allocated_bus);
        if (r < 0)
                return r;

        container_bus = allocated_bus ?: m->manager->bus;

        r = bus_message_new_method_call(container_bus, &tm, bus_systemd_mgr, "StartTransientUnit");
        if (r < 0)
                return r;

        /* Name and mode */
        unit = strjoina("container-shell@", p, ".service");
        r = sd_bus_message_append(tm, "ss", unit, "fail");
        if (r < 0)
                return r;

        /* Properties */
        r = sd_bus_message_open_container(tm, 'a', "(sv)");
        if (r < 0)
                return r;

        description = strjoina("Shell for User ", user);
        r = sd_bus_message_append(tm,
                                  "(sv)(sv)(sv)(sv)(sv)(sv)(sv)(sv)(sv)(sv)(sv)(sv)(sv)",
                                  "Description", "s", description,
                                  "StandardInputFileDescriptor", "h", slave,
                                  "StandardOutputFileDescriptor", "h", slave,
                                  "StandardErrorFileDescriptor", "h", slave,
                                  "SendSIGHUP", "b", true,
                                  "IgnoreSIGPIPE", "b", false,
                                  "KillMode", "s", "mixed",
                                  "TTYPath", "s", pty_name,
                                  "TTYReset", "b", true,
                                  "UtmpIdentifier", "s", utmp_id,
                                  "UtmpMode", "s", "user",
                                  "PAMName", "s", "login",
                                  "WorkingDirectory", "s", "-~");
        if (r < 0)
                return r;

        r = sd_bus_message_append(tm, "(sv)", "User", "s", user);
        if (r < 0)
                return r;

        if (!strv_isempty(env)) {
                r = sd_bus_message_open_container(tm, 'r', "sv");
                if (r < 0)
                        return r;

                r = sd_bus_message_append(tm, "s", "Environment");
                if (r < 0)
                        return r;

                r = sd_bus_message_open_container(tm, 'v', "as");
                if (r < 0)
                        return r;

                r = sd_bus_message_append_strv(tm, env);
                if (r < 0)
                        return r;

                r = sd_bus_message_close_container(tm);
                if (r < 0)
                        return r;

                r = sd_bus_message_close_container(tm);
                if (r < 0)
                        return r;
        }

        /* Exec container */
        r = sd_bus_message_open_container(tm, 'r', "sv");
        if (r < 0)
                return r;

        r = sd_bus_message_append(tm, "s", "ExecStart");
        if (r < 0)
                return r;

        r = sd_bus_message_open_container(tm, 'v', "a(sasb)");
        if (r < 0)
                return r;

        r = sd_bus_message_open_container(tm, 'a', "(sasb)");
        if (r < 0)
                return r;

        r = sd_bus_message_open_container(tm, 'r', "sasb");
        if (r < 0)
                return r;

        r = sd_bus_message_append(tm, "s", path);
        if (r < 0)
                return r;

        r = sd_bus_message_append_strv(tm, args);
        if (r < 0)
                return r;

        r = sd_bus_message_append(tm, "b", true);
        if (r < 0)
                return r;

        r = sd_bus_message_close_container(tm);
        if (r < 0)
                return r;

        r = sd_bus_message_close_container(tm);
        if (r < 0)
                return r;

        r = sd_bus_message_close_container(tm);
        if (r < 0)
                return r;

        r = sd_bus_message_close_container(tm);
        if (r < 0)
                return r;

        r = sd_bus_message_close_container(tm);
        if (r < 0)
                return r;

        /* Auxiliary units */
        r = sd_bus_message_append(tm, "a(sa(sv))", 0);
        if (r < 0)
                return r;

        r = sd_bus_call(container_bus, tm, 0, error, NULL);
        if (r < 0)
                return r;

        slave = safe_close(slave);

        r = sd_bus_message_new_method_return(message, &reply);
        if (r < 0)
                return r;

        r = sd_bus_message_append(reply, "hs", master, pty_name);
        if (r < 0)
                return r;

        return sd_bus_send(NULL, reply, NULL);
}

int bus_machine_method_bind_mount(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        int read_only, make_file_or_directory;
        const char *dest, *src, *propagate_directory;
        Machine *m = userdata;
        uid_t uid;
        int r;

        assert(message);
        assert(m);

        if (m->class != MACHINE_CONTAINER)
                return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Bind mounting is only supported on container machines.");

        r = sd_bus_message_read(message, "ssbb", &src, &dest, &read_only, &make_file_or_directory);
        if (r < 0)
                return r;

        if (!path_is_absolute(src) || !path_is_normalized(src))
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Source path must be absolute and normalized.");

        if (isempty(dest))
                dest = src;
        else if (!path_is_absolute(dest) || !path_is_normalized(dest))
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Destination path must be absolute and normalized.");

        r = bus_verify_polkit_async(
                        message,
                        CAP_SYS_ADMIN,
                        "org.freedesktop.machine1.manage-machines",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        r = machine_get_uid_shift(m, &uid);
        if (r < 0)
                return r;
        if (uid != 0)
                return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Can't bind mount on container with user namespacing applied.");

        propagate_directory = strjoina("/run/systemd/nspawn/propagate/", m->name);
        r = bind_mount_in_namespace(m->leader,
                                    propagate_directory,
                                    "/run/host/incoming/",
                                    src, dest, read_only, make_file_or_directory);
        if (r < 0)
                return sd_bus_error_set_errnof(error, r, "Failed to mount %s on %s in machine's namespace: %m", src, dest);

        return sd_bus_reply_method_return(message, NULL);
}

int bus_machine_method_copy(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        const char *src, *dest, *host_path, *container_path, *host_basename, *container_basename, *container_dirname;
        _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 };
        CopyFlags copy_flags = COPY_REFLINK|COPY_MERGE|COPY_HARDLINKS;
        _cleanup_close_ int hostfd = -1;
        Machine *m = userdata;
        bool copy_from;
        pid_t child;
        uid_t uid_shift;
        char *t;
        int r;

        assert(message);
        assert(m);

        if (m->manager->n_operations >= OPERATIONS_MAX)
                return sd_bus_error_set(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing copies.");

        if (m->class != MACHINE_CONTAINER)
                return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Copying files is only supported on container machines.");

        r = sd_bus_message_read(message, "ss", &src, &dest);
        if (r < 0)
                return r;

        if (!path_is_absolute(src))
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Source path must be absolute.");

        if (isempty(dest))
                dest = src;
        else if (!path_is_absolute(dest))
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Destination path must be absolute.");

        r = bus_verify_polkit_async(
                        message,
                        CAP_SYS_ADMIN,
                        "org.freedesktop.machine1.manage-machines",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        r = machine_get_uid_shift(m, &uid_shift);
        if (r < 0)
                return r;

        copy_from = strstr(sd_bus_message_get_member(message), "CopyFrom");

        if (copy_from) {
                container_path = src;
                host_path = dest;
        } else {
                host_path = src;
                container_path = dest;
        }

        host_basename = basename(host_path);

        container_basename = basename(container_path);
        t = strdupa(container_path);
        container_dirname = dirname(t);

        hostfd = open_parent(host_path, O_CLOEXEC, 0);
        if (hostfd < 0)
                return sd_bus_error_set_errnof(error, hostfd, "Failed to open host directory %s: %m", host_path);

        if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0)
                return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m");

        r = safe_fork("(sd-copy)", FORK_RESET_SIGNALS, &child);
        if (r < 0)
                return sd_bus_error_set_errnof(error, r, "Failed to fork(): %m");
        if (r == 0) {
                int containerfd;
                const char *q;
                int mntfd;

                errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);

                q = procfs_file_alloca(m->leader, "ns/mnt");
                mntfd = open(q, O_RDONLY|O_NOCTTY|O_CLOEXEC);
                if (mntfd < 0) {
                        r = log_error_errno(errno, "Failed to open mount namespace of leader: %m");
                        goto child_fail;
                }

                if (setns(mntfd, CLONE_NEWNS) < 0) {
                        r = log_error_errno(errno, "Failed to join namespace of leader: %m");
                        goto child_fail;
                }

                containerfd = open(container_dirname, O_CLOEXEC|O_RDONLY|O_NOCTTY|O_DIRECTORY);
                if (containerfd < 0) {
                        r = log_error_errno(errno, "Failed to open destination directory: %m");
                        goto child_fail;
                }

                /* Run the actual copy operation. Note that when an UID shift is set we'll either clamp the UID/GID to
                 * 0 or to the actual UID shift depending on the direction we copy. If no UID shift is set we'll copy
                 * the UID/GIDs as they are. */
                if (copy_from)
                        r = copy_tree_at(containerfd, container_basename, hostfd, host_basename, uid_shift == 0 ? UID_INVALID : 0, uid_shift == 0 ? GID_INVALID : 0, copy_flags);
                else
                        r = copy_tree_at(hostfd, host_basename, containerfd, container_basename, uid_shift == 0 ? UID_INVALID : uid_shift, uid_shift == 0 ? GID_INVALID : uid_shift, copy_flags);

                hostfd = safe_close(hostfd);
                containerfd = safe_close(containerfd);

                if (r < 0) {
                        r = log_error_errno(r, "Failed to copy tree: %m");
                        goto child_fail;
                }

                _exit(EXIT_SUCCESS);

        child_fail:
                (void) write(errno_pipe_fd[1], &r, sizeof(r));
                _exit(EXIT_FAILURE);
        }

        errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]);

        /* Copying might take a while, hence install a watch on the child, and return */

        r = operation_new(m->manager, m, child, message, errno_pipe_fd[0], NULL);
        if (r < 0) {
                (void) sigkill_wait(child);
                return r;
        }
        errno_pipe_fd[0] = -1;

        return 1;
}

int bus_machine_method_open_root_directory(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        _cleanup_close_ int fd = -1;
        Machine *m = userdata;
        int r;

        assert(message);
        assert(m);

        r = bus_verify_polkit_async(
                        message,
                        CAP_SYS_ADMIN,
                        "org.freedesktop.machine1.manage-machines",
                        NULL,
                        false,
                        UID_INVALID,
                        &m->manager->polkit_registry,
                        error);
        if (r < 0)
                return r;
        if (r == 0)
                return 1; /* Will call us back */

        switch (m->class) {

        case MACHINE_HOST:
                fd = open("/", O_RDONLY|O_CLOEXEC|O_DIRECTORY);
                if (fd < 0)
                        return -errno;

                break;

        case MACHINE_CONTAINER: {
                _cleanup_close_ int mntns_fd = -1, root_fd = -1;
                _cleanup_close_pair_ int pair[2] = { -1, -1 };
                pid_t child;

                r = namespace_open(m->leader, NULL, &mntns_fd, NULL, NULL, &root_fd);
                if (r < 0)
                        return r;

                if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0)
                        return -errno;

                r = namespace_fork("(sd-openrootns)", "(sd-openroot)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG,
                                   -1, mntns_fd, -1, -1, root_fd, &child);
                if (r < 0)
                        return sd_bus_error_set_errnof(error, r, "Failed to fork(): %m");
                if (r == 0) {
                        _cleanup_close_ int dfd = -1;

                        pair[0] = safe_close(pair[0]);

                        dfd = open("/", O_RDONLY|O_CLOEXEC|O_DIRECTORY);
                        if (dfd < 0)
                                _exit(EXIT_FAILURE);

                        r = send_one_fd(pair[1], dfd, 0);
                        dfd = safe_close(dfd);
                        if (r < 0)
                                _exit(EXIT_FAILURE);

                        _exit(EXIT_SUCCESS);
                }

                pair[1] = safe_close(pair[1]);

                r = wait_for_terminate_and_check("(sd-openrootns)", child, 0);
                if (r < 0)
                        return sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m");
                if (r != EXIT_SUCCESS)
                        return sd_bus_error_set(error, SD_BUS_ERROR_FAILED, "Child died abnormally.");

                fd = receive_one_fd(pair[0], MSG_DONTWAIT);
                if (fd < 0)
                        return fd;

                break;
        }

        default:
                return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "Opening the root directory is only supported on container machines.");
        }

        return sd_bus_reply_method_return(message, "h", fd);
}

int bus_machine_method_get_uid_shift(sd_bus_message *message, void *userdata, sd_bus_error *error) {
        Machine *m = userdata;
        uid_t shift = 0;
        int r;

        assert(message);
        assert(m);

        /* You wonder why this is a method and not a property? Well, properties are not supposed to return errors, but
         * we kinda have to for this. */

        if (m->class == MACHINE_HOST)
                return sd_bus_reply_method_return(message, "u", UINT32_C(0));

        if (m->class != MACHINE_CONTAINER)
                return sd_bus_error_set(error, SD_BUS_ERROR_NOT_SUPPORTED, "UID/GID shift may only be determined for container machines.");

        r = machine_get_uid_shift(m, &shift);
        if (r == -ENXIO)
                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Machine %s uses a complex UID/GID mapping, cannot determine shift", m->name);
        if (r < 0)
                return r;

        return sd_bus_reply_method_return(message, "u", (uint32_t) shift);
}

static int machine_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
        Manager *m = userdata;
        Machine *machine;
        int r;

        assert(bus);
        assert(path);
        assert(interface);
        assert(found);
        assert(m);

        if (streq(path, "/org/freedesktop/machine1/machine/self")) {
                _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
                sd_bus_message *message;
                pid_t pid;

                message = sd_bus_get_current_message(bus);
                if (!message)
                        return 0;

                r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_PID, &creds);
                if (r < 0)
                        return r;

                r = sd_bus_creds_get_pid(creds, &pid);
                if (r < 0)
                        return r;

                r = manager_get_machine_by_pid(m, pid, &machine);
                if (r <= 0)
                        return 0;
        } else {
                _cleanup_free_ char *e = NULL;
                const char *p;

                p = startswith(path, "/org/freedesktop/machine1/machine/");
                if (!p)
                        return 0;

                e = bus_label_unescape(p);
                if (!e)
                        return -ENOMEM;

                machine = hashmap_get(m->machines, e);
                if (!machine)
                        return 0;
        }

        *found = machine;
        return 1;
}

char *machine_bus_path(Machine *m) {
        _cleanup_free_ char *e = NULL;

        assert(m);

        e = bus_label_escape(m->name);
        if (!e)
                return NULL;

        return strjoin("/org/freedesktop/machine1/machine/", e);
}

static int machine_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
        _cleanup_strv_free_ char **l = NULL;
        Machine *machine = NULL;
        Manager *m = userdata;
        int r;

        assert(bus);
        assert(path);
        assert(nodes);

        HASHMAP_FOREACH(machine, m->machines) {
                char *p;

                p = machine_bus_path(machine);
                if (!p)
                        return -ENOMEM;

                r = strv_consume(&l, p);
                if (r < 0)
                        return r;
        }

        *nodes = TAKE_PTR(l);

        return 1;
}

static const sd_bus_vtable machine_vtable[] = {
        SD_BUS_VTABLE_START(0),
        SD_BUS_PROPERTY("Name", "s", NULL, offsetof(Machine, name), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("Id", "ay", bus_property_get_id128, offsetof(Machine, id), SD_BUS_VTABLE_PROPERTY_CONST),
        BUS_PROPERTY_DUAL_TIMESTAMP("Timestamp", offsetof(Machine, timestamp), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("Service", "s", NULL, offsetof(Machine, service), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("Unit", "s", NULL, offsetof(Machine, unit), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("Scope", "s", NULL, offsetof(Machine, unit), SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
        SD_BUS_PROPERTY("Leader", "u", NULL, offsetof(Machine, leader), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("Class", "s", property_get_class, offsetof(Machine, class), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("RootDirectory", "s", NULL, offsetof(Machine, root_directory), SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("NetworkInterfaces", "ai", property_get_netif, 0, SD_BUS_VTABLE_PROPERTY_CONST),
        SD_BUS_PROPERTY("State", "s", property_get_state, 0, 0),

        SD_BUS_METHOD("Terminate",
                      NULL,
                      NULL,
                      bus_machine_method_terminate,
                      SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("Kill",
                                 "si",
                                 SD_BUS_PARAM(who)
                                 SD_BUS_PARAM(signal),
                                 NULL,,
                                 bus_machine_method_kill,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("GetAddresses",
                                 NULL,,
                                 "a(iay)",
                                 SD_BUS_PARAM(addresses),
                                 bus_machine_method_get_addresses,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("GetOSRelease",
                                 NULL,,
                                 "a{ss}",
                                 SD_BUS_PARAM(fields),
                                 bus_machine_method_get_os_release,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("GetUIDShift",
                                 NULL,,
                                 "u",
                                 SD_BUS_PARAM(shift),
                                 bus_machine_method_get_uid_shift,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("OpenPTY",
                                 NULL,,
                                 "hs",
                                 SD_BUS_PARAM(pty)
                                 SD_BUS_PARAM(pty_path),
                                 bus_machine_method_open_pty,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("OpenLogin",
                                 NULL,,
                                 "hs",
                                 SD_BUS_PARAM(pty)
                                 SD_BUS_PARAM(pty_path),
                                 bus_machine_method_open_login,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("OpenShell",
                                 "ssasas",
                                 SD_BUS_PARAM(user)
                                 SD_BUS_PARAM(path)
                                 SD_BUS_PARAM(args)
                                 SD_BUS_PARAM(environment),
                                 "hs",
                                 SD_BUS_PARAM(pty)
                                 SD_BUS_PARAM(pty_path),
                                 bus_machine_method_open_shell,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("BindMount",
                                 "ssbb",
                                 SD_BUS_PARAM(source)
                                 SD_BUS_PARAM(destination)
                                 SD_BUS_PARAM(read_only)
                                 SD_BUS_PARAM(mkdir),
                                 NULL,,
                                 bus_machine_method_bind_mount,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("CopyFrom",
                                 "ss",
                                 SD_BUS_PARAM(source)
                                 SD_BUS_PARAM(destination),
                                 NULL,,
                                 bus_machine_method_copy,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("CopyTo",
                                 "ss",
                                 SD_BUS_PARAM(source)
                                 SD_BUS_PARAM(destination),
                                 NULL,,
                                 bus_machine_method_copy,
                                 SD_BUS_VTABLE_UNPRIVILEGED),
        SD_BUS_METHOD_WITH_NAMES("OpenRootDirectory",
                                 NULL,,
                                 "h",
                                 SD_BUS_PARAM(fd),
                                 bus_machine_method_open_root_directory,
                                 SD_BUS_VTABLE_UNPRIVILEGED),

        SD_BUS_VTABLE_END
};

const BusObjectImplementation machine_object = {
        "/org/freedesktop/machine1/machine",
        "org.freedesktop.machine1.Machine",
        .fallback_vtables = BUS_FALLBACK_VTABLES({machine_vtable, machine_object_find}),
        .node_enumerator = machine_node_enumerator,
};

int machine_send_signal(Machine *m, bool new_machine) {
        _cleanup_free_ char *p = NULL;

        assert(m);

        p = machine_bus_path(m);
        if (!p)
                return -ENOMEM;

        return sd_bus_emit_signal(
                        m->manager->bus,
                        "/org/freedesktop/machine1",
                        "org.freedesktop.machine1.Manager",
                        new_machine ? "MachineNew" : "MachineRemoved",
                        "so", m->name, p);
}

int machine_send_create_reply(Machine *m, sd_bus_error *error) {
        _cleanup_(sd_bus_message_unrefp) sd_bus_message *c = NULL;
        _cleanup_free_ char *p = NULL;

        assert(m);

        if (!m->create_message)
                return 0;

        c = TAKE_PTR(m->create_message);

        if (error)
                return sd_bus_reply_method_error(c, error);

        /* Update the machine state file before we notify the client
         * about the result. */
        machine_save(m);

        p = machine_bus_path(m);
        if (!p)
                return -ENOMEM;

        return sd_bus_reply_method_return(c, "o", p);
}