Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 198 insertions, 0 deletions

diff --git a/src/login/user-runtime-dir.c b/src/login/user-runtime-dir.c
new file mode 100644
index 0000000..eb66e18
--- /dev/null
+++ b/src/login/user-runtime-dir.c
@@ -0,0 +1,198 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <stdint.h>
+#include <sys/mount.h>
+
+#include "sd-bus.h"
+
+#include "bus-error.h"
+#include "fs-util.h"
+#include "label.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "mountpoint-util.h"
+#include "path-util.h"
+#include "rm-rf.h"
+#include "selinux-util.h"
+#include "smack-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "user-util.h"
+
+static int acquire_runtime_dir_size(uint64_t *ret) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        int r;
+
+        r = sd_bus_default_system(&bus);
+        if (r < 0)
+                return log_error_errno(r, "Failed to connect to system bus: %m");
+
+        r = sd_bus_get_property_trivial(bus, "org.freedesktop.login1", "/org/freedesktop/login1", "org.freedesktop.login1.Manager", "RuntimeDirectorySize", &error, 't', ret);
+        if (r < 0)
+                return log_error_errno(r, "Failed to acquire runtime directory size: %s", bus_error_message(&error, r));
+
+        return 0;
+}
+
+static int user_mkdir_runtime_path(
+                const char *runtime_path,
+                uid_t uid,
+                gid_t gid,
+                uint64_t runtime_dir_size) {
+
+        int r;
+
+        assert(runtime_path);
+        assert(path_is_absolute(runtime_path));
+        assert(uid_is_valid(uid));
+        assert(gid_is_valid(gid));
+
+        r = mkdir_safe_label("/run/user", 0755, 0, 0, MKDIR_WARN_MODE);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/user: %m");
+
+        if (path_is_mount_point(runtime_path, NULL, 0) >= 0)
+                log_debug("%s is already a mount point", runtime_path);
+        else {
+                char options[sizeof("mode=0700,uid=,gid=,size=,smackfsroot=*")
+                             + DECIMAL_STR_MAX(uid_t)
+                             + DECIMAL_STR_MAX(gid_t)
+                             + DECIMAL_STR_MAX(uint64_t)];
+
+                xsprintf(options,
+                         "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%" PRIu64 "%s",
+                         uid, gid, runtime_dir_size,
+                         mac_smack_use() ? ",smackfsroot=*" : "");
+
+                (void) mkdir_label(runtime_path, 0700);
+
+                r = mount("tmpfs", runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, options);
+                if (r < 0) {
+                        if (!IN_SET(errno, EPERM, EACCES)) {
+                                r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", runtime_path);
+                                goto fail;
+                        }
+
+                        log_debug_errno(errno, "Failed to mount per-user tmpfs directory %s.\n"
+                                        "Assuming containerized execution, ignoring: %m", runtime_path);
+
+                        r = chmod_and_chown(runtime_path, 0700, uid, gid);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to change ownership and mode of \"%s\": %m", runtime_path);
+                                goto fail;
+                        }
+                }
+
+                r = label_fix(runtime_path, 0);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to fix label of \"%s\", ignoring: %m", runtime_path);
+        }
+
+        return 0;
+
+fail:
+        /* Try to clean up, but ignore errors */
+        (void) rmdir(runtime_path);
+        return r;
+}
+
+static int user_remove_runtime_path(const char *runtime_path) {
+        int r;
+
+        assert(runtime_path);
+        assert(path_is_absolute(runtime_path));
+
+        r = rm_rf(runtime_path, 0);
+        if (r < 0)
+                log_debug_errno(r, "Failed to remove runtime directory %s (before unmounting), ignoring: %m", runtime_path);
+
+        /* Ignore cases where the directory isn't mounted, as that's quite possible, if we lacked the permissions to
+         * mount something */
+        r = umount2(runtime_path, MNT_DETACH);
+        if (r < 0 && !IN_SET(errno, EINVAL, ENOENT))
+                log_debug_errno(errno, "Failed to unmount user runtime directory %s, ignoring: %m", runtime_path);
+
+        r = rm_rf(runtime_path, REMOVE_ROOT);
+        if (r < 0 && r != -ENOENT)
+                return log_error_errno(r, "Failed to remove runtime directory %s (after unmounting): %m", runtime_path);
+
+        return 0;
+}
+
+static int do_mount(const char *user) {
+        char runtime_path[sizeof("/run/user") + DECIMAL_STR_MAX(uid_t)];
+        uint64_t runtime_dir_size;
+        uid_t uid;
+        gid_t gid;
+        int r;
+
+        r = get_user_creds(&user, &uid, &gid, NULL, NULL, 0);
+        if (r < 0)
+                return log_error_errno(r,
+                                       r == -ESRCH ? "No such user \"%s\"" :
+                                       r == -ENOMSG ? "UID \"%s\" is invalid or has an invalid main group"
+                                                    : "Failed to look up user \"%s\": %m",
+                                       user);
+
+        r = acquire_runtime_dir_size(&runtime_dir_size);
+        if (r < 0)
+                return r;
+
+        xsprintf(runtime_path, "/run/user/" UID_FMT, uid);
+
+        log_debug("Will mount %s owned by "UID_FMT":"GID_FMT, runtime_path, uid, gid);
+        return user_mkdir_runtime_path(runtime_path, uid, gid, runtime_dir_size);
+}
+
+static int do_umount(const char *user) {
+        char runtime_path[sizeof("/run/user") + DECIMAL_STR_MAX(uid_t)];
+        uid_t uid;
+        int r;
+
+        /* The user may be already removed. So, first try to parse the string by parse_uid(),
+         * and if it fails, fallback to get_user_creds().*/
+        if (parse_uid(user, &uid) < 0) {
+                r = get_user_creds(&user, &uid, NULL, NULL, NULL, 0);
+                if (r < 0)
+                        return log_error_errno(r,
+                                               r == -ESRCH ? "No such user \"%s\"" :
+                                               r == -ENOMSG ? "UID \"%s\" is invalid or has an invalid main group"
+                                                            : "Failed to look up user \"%s\": %m",
+                                               user);
+        }
+
+        xsprintf(runtime_path, "/run/user/" UID_FMT, uid);
+
+        log_debug("Will remove %s", runtime_path);
+        return user_remove_runtime_path(runtime_path);
+}
+
+static int run(int argc, char *argv[]) {
+        int r;
+
+        log_parse_environment();
+        log_open();
+
+        if (argc != 3)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "This program takes two arguments.");
+        if (!STR_IN_SET(argv[1], "start", "stop"))
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "First argument must be either \"start\" or \"stop\".");
+
+        r = mac_selinux_init();
+        if (r < 0)
+                return log_error_errno(r, "Could not initialize labelling: %m\n");
+
+        umask(0022);
+
+        if (streq(argv[1], "start"))
+                return do_mount(argv[2]);
+        if (streq(argv[1], "stop"))
+                return do_umount(argv[2]);
+        assert_not_reached("Unknown verb!");
+}
+
+DEFINE_MAIN_FUNCTION(run);