Ensure kdbus isn't used (#3501)

Delete the dbus1 generator and some critical wiring. This prevents
kdbus from being loaded or detected. As such, it will never be used,
even if the user still has a useful kdbus module loaded on their system.

Sort of fixes #3480. Not really, but it's better than the current state.

9 files changed, 17 insertions, 434 deletions

diff --git a/src/core/busname.c b/src/core/busname.c
index f03a95c24e..730be2ee14 100644
--- a/src/core/busname.c
+++ b/src/core/busname.c
@@ -998,12 +998,7 @@ static int busname_get_timeout(Unit *u, usec_t *timeout) {
 }
 
 static bool busname_supported(void) {
-        static int supported = -1;
-
-        if (supported < 0)
-                supported = is_kdbus_available();
-
-        return supported;
+        return false;
 }
 
 static int busname_control_pid(Unit *u) {
diff --git a/src/core/kmod-setup.c b/src/core/kmod-setup.c
index 3503db52ed..fd1021f706 100644
--- a/src/core/kmod-setup.c
+++ b/src/core/kmod-setup.c
@@ -64,9 +64,6 @@ int kmod_setup(void) {
                 /* this should never be a module */
                 { "unix",      "/proc/net/unix",            true,   true,    NULL      },
 
-                /* IPC is needed before we bring up any other services */
-                { "kdbus",     "/sys/fs/kdbus",             false,  false,   is_kdbus_wanted },
-
 #ifdef HAVE_LIBIPTC
                 /* netfilter is needed by networkd, nspawn among others, and cannot be autoloaded */
                 { "ip_tables", "/proc/net/ip_tables_names", false,  false,   NULL      },
diff --git a/src/core/manager.c b/src/core/manager.c
index 5c0fee935d..012aa6cd53 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -814,28 +814,6 @@ static int manager_setup_cgroups_agent(Manager *m) {
         return 0;
 }
 
-static int manager_setup_kdbus(Manager *m) {
-        _cleanup_free_ char *p = NULL;
-
-        assert(m);
-
-        if (m->test_run || m->kdbus_fd >= 0)
-                return 0;
-        if (!is_kdbus_available())
-                return -ESOCKTNOSUPPORT;
-
-        m->kdbus_fd = bus_kernel_create_bus(
-                        MANAGER_IS_SYSTEM(m) ? "system" : "user",
-                        MANAGER_IS_SYSTEM(m), &p);
-
-        if (m->kdbus_fd < 0)
-                return log_debug_errno(m->kdbus_fd, "Failed to set up kdbus: %m");
-
-        log_debug("Successfully set up kdbus on %s", p);
-
-        return 0;
-}
-
 static int manager_connect_bus(Manager *m, bool reexecuting) {
         bool try_bus_connect;
 
@@ -1244,7 +1222,6 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 
         /* We might have deserialized the kdbus control fd, but if we
          * didn't, then let's create the bus now. */
-        manager_setup_kdbus(m);
         manager_connect_bus(m, !!serialization);
         bus_track_coldplug(m, &m->subscribed, &m->deserialized_subscribed);
 
diff --git a/src/core/mount-setup.c b/src/core/mount-setup.c
index 40fc548b42..f9c9b4a91f 100644
--- a/src/core/mount-setup.c
+++ b/src/core/mount-setup.c
@@ -108,8 +108,6 @@ static const MountPoint mount_table[] = {
         { "efivarfs",    "/sys/firmware/efi/efivars", "efivarfs",   NULL,                      MS_NOSUID|MS_NOEXEC|MS_NODEV,
           is_efi_boot,   MNT_NONE                   },
 #endif
-        { "kdbusfs",    "/sys/fs/kdbus",             "kdbusfs",    NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
-          is_kdbus_wanted,       MNT_IN_CONTAINER },
 };
 
 /* These are API file systems that might be mounted by other software,
diff --git a/src/core/service.c b/src/core/service.c
index 14da6a58a9..78c33b1530 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -574,20 +574,9 @@ static int service_setup_bus_name(Service *s) {
         if (!s->bus_name)
                 return 0;
 
-        if (is_kdbus_available()) {
-                const char *n;
-
-                n = strjoina(s->bus_name, ".busname");
-                r = unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, n, NULL, true);
-                if (r < 0)
-                        return log_unit_error_errno(UNIT(s), r, "Failed to add dependency to .busname unit: %m");
-
-        } else {
-                /* If kdbus is not available, we know the dbus socket is required, hence pull it in, and require it */
-                r = unit_add_dependency_by_name(UNIT(s), UNIT_REQUIRES, SPECIAL_DBUS_SOCKET, NULL, true);
-                if (r < 0)
-                        return log_unit_error_errno(UNIT(s), r, "Failed to add dependency on " SPECIAL_DBUS_SOCKET ": %m");
-        }
+        r = unit_add_dependency_by_name(UNIT(s), UNIT_REQUIRES, SPECIAL_DBUS_SOCKET, NULL, true);
+        if (r < 0)
+                return log_unit_error_errno(UNIT(s), r, "Failed to add dependency on " SPECIAL_DBUS_SOCKET ": %m");
 
         /* Regardless if kdbus is used or not, we always want to be ordered against dbus.socket if both are in the transaction. */
         r = unit_add_dependency_by_name(UNIT(s), UNIT_AFTER, SPECIAL_DBUS_SOCKET, NULL, true);
diff --git a/src/dbus1-generator/dbus1-generator.c b/src/dbus1-generator/dbus1-generator.c
deleted file mode 100644
index 717cb9558e..0000000000
--- a/src/dbus1-generator/dbus1-generator.c
+++ /dev/null
@@ -1,331 +0,0 @@
-/***
-  This file is part of systemd.
-
-  Copyright 2013 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include "alloc-util.h"
-#include "bus-internal.h"
-#include "bus-util.h"
-#include "cgroup-util.h"
-#include "conf-parser.h"
-#include "dirent-util.h"
-#include "fd-util.h"
-#include "fileio.h"
-#include "mkdir.h"
-#include "special.h"
-#include "unit-name.h"
-#include "util.h"
-
-static const char *arg_dest_late = "/tmp", *arg_dest = "/tmp";
-
-static int create_dbus_files(
-                const char *path,
-                const char *name,
-                const char *service,
-                const char *exec,
-                const char *user,
-                const char *type) {
-
-        _cleanup_free_ char *b = NULL, *s = NULL, *lnk = NULL;
-        _cleanup_fclose_ FILE *f = NULL;
-        int r;
-
-        assert(path);
-        assert(name);
-        assert(service || exec);
-
-        if (!service) {
-                _cleanup_free_ char *a = NULL;
-
-                s = strjoin("dbus-", name, ".service", NULL);
-                if (!s)
-                        return log_oom();
-
-                a = strjoin(arg_dest_late, "/", s, NULL);
-                if (!a)
-                        return log_oom();
-
-                f = fopen(a, "wxe");
-                if (!f)
-                        return log_error_errno(errno, "Failed to create %s: %m", a);
-
-                fprintf(f,
-                        "# Automatically generated by systemd-dbus1-generator\n\n"
-                        "[Unit]\n"
-                        "SourcePath=%s\n"
-                        "Description=DBUS1: %s\n"
-                        "Documentation=man:systemd-dbus1-generator(8)\n\n"
-                        "[Service]\n"
-                        "ExecStart=%s\n"
-                        "Type=dbus\n"
-                        "BusName=%s\n",
-                        path,
-                        name,
-                        exec,
-                        name);
-
-                if (user)
-                        fprintf(f, "User=%s\n", user);
-
-
-                if (type) {
-                        fprintf(f, "Environment=DBUS_STARTER_BUS_TYPE=%s\n", type);
-
-                        if (streq(type, "system"))
-                                fprintf(f, "Environment=DBUS_STARTER_ADDRESS=" DEFAULT_SYSTEM_BUS_ADDRESS "\n");
-                        else if (streq(type, "session")) {
-                                char *run;
-
-                                run = getenv("XDG_RUNTIME_DIR");
-                                if (!run) {
-                                        log_error("XDG_RUNTIME_DIR not set.");
-                                        return -EINVAL;
-                                }
-
-                                fprintf(f, "Environment=DBUS_STARTER_ADDRESS="KERNEL_USER_BUS_ADDRESS_FMT ";" UNIX_USER_BUS_ADDRESS_FMT "\n",
-                                        getuid(), run);
-                        }
-                }
-
-                r = fflush_and_check(f);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to write %s: %m", a);
-
-                f = safe_fclose(f);
-
-                service = s;
-        }
-
-        b = strjoin(arg_dest_late, "/", name, ".busname", NULL);
-        if (!b)
-                return log_oom();
-
-        f = fopen(b, "wxe");
-        if (!f)
-                return log_error_errno(errno, "Failed to create %s: %m", b);
-
-        fprintf(f,
-                "# Automatically generated by systemd-dbus1-generator\n\n"
-                "[Unit]\n"
-                "SourcePath=%s\n"
-                "Description=DBUS1: %s\n"
-                "Documentation=man:systemd-dbus1-generator(8)\n\n"
-                "[BusName]\n"
-                "Name=%s\n"
-                "Service=%s\n"
-                "AllowWorld=talk\n",
-                path,
-                name,
-                name,
-                service);
-
-        r = fflush_and_check(f);
-        if (r < 0)
-                return log_error_errno(r, "Failed to write %s: %m", b);
-
-        lnk = strjoin(arg_dest_late, "/" SPECIAL_BUSNAMES_TARGET ".wants/", name, ".busname", NULL);
-        if (!lnk)
-                return log_oom();
-
-        mkdir_parents_label(lnk, 0755);
-        if (symlink(b, lnk))
-                return log_error_errno(errno, "Failed to create symlink %s: %m", lnk);
-
-        return 0;
-}
-
-static int add_dbus(const char *path, const char *fname, const char *type) {
-        _cleanup_free_ char *name = NULL, *exec = NULL, *user = NULL, *service = NULL;
-
-        const ConfigTableItem table[] = {
-                { "D-BUS Service", "Name", config_parse_string, 0, &name },
-                { "D-BUS Service", "Exec", config_parse_string, 0, &exec },
-                { "D-BUS Service", "User", config_parse_string, 0, &user },
-                { "D-BUS Service", "SystemdService", config_parse_string, 0, &service },
-                { },
-        };
-
-        char *p;
-        int r;
-
-        assert(path);
-        assert(fname);
-
-        p = strjoina(path, "/", fname);
-        r = config_parse(NULL, p, NULL,
-                         "D-BUS Service\0",
-                         config_item_table_lookup, table,
-                         true, false, true, NULL);
-        if (r < 0)
-                return r;
-
-        if (!name) {
-                log_warning("Activation file %s lacks name setting, ignoring.", p);
-                return 0;
-        }
-
-        if (!service_name_is_valid(name)) {
-                log_warning("Bus service name %s is not valid, ignoring.", name);
-                return 0;
-        }
-
-        if (streq(name, "org.freedesktop.systemd1")) {
-                log_debug("Skipping %s, identified as systemd.", p);
-                return 0;
-        }
-
-        if (service) {
-                if (!unit_name_is_valid(service, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE)) {
-                        log_warning("Unit name %s is not valid, ignoring.", service);
-                        return 0;
-                }
-                if (!endswith(service, ".service")) {
-                        log_warning("Bus names can only activate services, ignoring %s.", p);
-                        return 0;
-                }
-        } else {
-                if (streq(exec, "/bin/false") || !exec) {
-                        log_warning("Neither service name nor binary path specified, ignoring %s.", p);
-                        return 0;
-                }
-
-                if (exec[0] != '/') {
-                        log_warning("Exec= in %s does not start with an absolute path, ignoring.", p);
-                        return 0;
-                }
-        }
-
-        return create_dbus_files(p, name, service, exec, user, type);
-}
-
-static int parse_dbus_fragments(const char *path, const char *type) {
-        _cleanup_closedir_ DIR *d = NULL;
-        struct dirent *de;
-        int r;
-
-        assert(path);
-        assert(type);
-
-        d = opendir(path);
-        if (!d) {
-                if (errno == -ENOENT)
-                        return 0;
-
-                return log_error_errno(errno, "Failed to enumerate D-Bus activated services: %m");
-        }
-
-        r = 0;
-        FOREACH_DIRENT(de, d, goto fail) {
-                int q;
-
-                if (!endswith(de->d_name, ".service"))
-                        continue;
-
-                q = add_dbus(path, de->d_name, type);
-                if (q < 0)
-                        r = q;
-        }
-
-        return r;
-
-fail:
-        return log_error_errno(errno, "Failed to read D-Bus services directory: %m");
-}
-
-static int link_busnames_target(const char *units) {
-        const char *f, *t;
-
-        f = strjoina(units, "/" SPECIAL_BUSNAMES_TARGET);
-        t = strjoina(arg_dest, "/" SPECIAL_BASIC_TARGET ".wants/" SPECIAL_BUSNAMES_TARGET);
-
-        mkdir_parents_label(t, 0755);
-        if (symlink(f, t) < 0)
-                return log_error_errno(errno, "Failed to create symlink %s: %m", t);
-
-        return 0;
-}
-
-static int link_compatibility(const char *units) {
-        const char *f, *t;
-
-        f = strjoina(units, "/systemd-bus-proxyd.socket");
-        t = strjoina(arg_dest, "/" SPECIAL_DBUS_SOCKET);
-        mkdir_parents_label(t, 0755);
-        if (symlink(f, t) < 0)
-                return log_error_errno(errno, "Failed to create symlink %s: %m", t);
-
-        f = strjoina(units, "/systemd-bus-proxyd.socket");
-        t = strjoina(arg_dest, "/" SPECIAL_SOCKETS_TARGET ".wants/systemd-bus-proxyd.socket");
-        mkdir_parents_label(t, 0755);
-        if (symlink(f, t) < 0)
-                return log_error_errno(errno, "Failed to create symlink %s: %m", t);
-
-        t = strjoina(arg_dest, "/" SPECIAL_DBUS_SERVICE);
-        if (symlink("/dev/null", t) < 0)
-                return log_error_errno(errno, "Failed to mask %s: %m", t);
-
-        return 0;
-}
-
-int main(int argc, char *argv[]) {
-        const char *path, *type, *units;
-        int r, q;
-
-        if (argc > 1 && argc != 4) {
-                log_error("This program takes three or no arguments.");
-                return EXIT_FAILURE;
-        }
-
-        if (argc > 1) {
-                arg_dest = argv[1];
-                arg_dest_late = argv[3];
-        }
-
-        log_set_target(LOG_TARGET_SAFE);
-        log_parse_environment();
-        log_open();
-
-        umask(0022);
-
-        if (!is_kdbus_available())
-                return 0;
-
-        r = cg_pid_get_owner_uid(0, NULL);
-        if (r >= 0) {
-                path = "/usr/share/dbus-1/services";
-                type = "session";
-                units = USER_DATA_UNIT_PATH;
-        } else if (r == -ENXIO) {
-                path = "/usr/share/dbus-1/system-services";
-                type = "system";
-                units = SYSTEM_DATA_UNIT_PATH;
-        } else
-                return log_error_errno(r, "Failed to determine whether we are running as user or system instance: %m");
-
-        r = parse_dbus_fragments(path, type);
-
-        /* FIXME: One day this should just be pulled in statically from basic.target */
-        q = link_busnames_target(units);
-        if (q < 0)
-                r = q;
-
-        q = link_compatibility(units);
-        if (q < 0)
-                r = q;
-
-        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
-}
diff --git a/src/login/pam_systemd.c b/src/login/pam_systemd.c
index 98dc201340..4f023640f6 100644
--- a/src/login/pam_systemd.c
+++ b/src/login/pam_systemd.c
@@ -182,25 +182,20 @@ static int export_legacy_dbus_address(
         _cleanup_free_ char *s = NULL;
         int r = PAM_BUF_ERR;
 
-        if (is_kdbus_available()) {
-                if (asprintf(&s, KERNEL_USER_BUS_ADDRESS_FMT ";" UNIX_USER_BUS_ADDRESS_FMT, uid, runtime) < 0)
-                        goto error;
-        } else {
-                /* FIXME: We *really* should move the access() check into the
-                 * daemons that spawn dbus-daemon, instead of forcing
-                 * DBUS_SESSION_BUS_ADDRESS= here. */
-
-                s = strjoin(runtime, "/bus", NULL);
-                if (!s)
-                        goto error;
-
-                if (access(s, F_OK) < 0)
-                        return PAM_SUCCESS;
+        /* FIXME: We *really* should move the access() check into the
+         * daemons that spawn dbus-daemon, instead of forcing
+         * DBUS_SESSION_BUS_ADDRESS= here. */
 
-                s = mfree(s);
-                if (asprintf(&s, UNIX_USER_BUS_ADDRESS_FMT, runtime) < 0)
-                        goto error;
-        }
+        s = strjoin(runtime, "/bus", NULL);
+        if (!s)
+                goto error;
+
+        if (access(s, F_OK) < 0)
+                return PAM_SUCCESS;
+
+        s = mfree(s);
+        if (asprintf(&s, UNIX_USER_BUS_ADDRESS_FMT, runtime) < 0)
+                goto error;
 
         r = pam_misc_setenv(handle, "DBUS_SESSION_BUS_ADDRESS", s, 0);
         if (r != PAM_SUCCESS)
diff --git a/src/shared/bus-util.c b/src/shared/bus-util.c
index 8cfa936347..8e3307dc24 100644
--- a/src/shared/bus-util.c
+++ b/src/shared/bus-util.c
@@ -1505,40 +1505,6 @@ int bus_path_decode_unique(const char *path, const char *prefix, char **ret_send
         return 1;
 }
 
-bool is_kdbus_wanted(void) {
-        _cleanup_free_ char *value = NULL;
-#ifdef ENABLE_KDBUS
-        const bool configured = true;
-#else
-        const bool configured = false;
-#endif
-
-        int r;
-
-        if (get_proc_cmdline_key("kdbus", NULL) > 0)
-                return true;
-
-        r = get_proc_cmdline_key("kdbus=", &value);
-        if (r <= 0)
-                return configured;
-
-        return parse_boolean(value) == 1;
-}
-
-bool is_kdbus_available(void) {
-        _cleanup_close_ int fd = -1;
-        struct kdbus_cmd cmd = { .size = sizeof(cmd), .flags = KDBUS_FLAG_NEGOTIATE };
-
-        if (!is_kdbus_wanted())
-                return false;
-
-        fd = open("/sys/fs/kdbus/control", O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
-        if (fd < 0)
-                return false;
-
-        return ioctl(fd, KDBUS_CMD_BUS_MAKE, &cmd) >= 0;
-}
-
 int bus_property_get_rlimit(
                 sd_bus *bus,
                 const char *path,
diff --git a/src/shared/bus-util.h b/src/shared/bus-util.h
index d792258ecd..db6b1acba2 100644
--- a/src/shared/bus-util.h
+++ b/src/shared/bus-util.h
@@ -157,7 +157,4 @@ int bus_log_create_error(int r);
 int bus_path_encode_unique(sd_bus *b, const char *prefix, const char *sender_id, const char *external_id, char **ret_path);
 int bus_path_decode_unique(const char *path, const char *prefix, char **ret_sender, char **ret_external);
 
-bool is_kdbus_wanted(void);
-bool is_kdbus_available(void);
-
 int bus_property_get_rlimit(sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *reply, void *userdata, sd_bus_error *error);