-/*-*- Mode: C; c-basic-offset: 8 -*-*/
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
#include <security/pam_ext.h>
#include <security/pam_misc.h>
-#include <libcgroup.h>
-
#include "util.h"
#include "cgroup-util.h"
#include "macro.h"
#include "sd-daemon.h"
+#include "strv.h"
static int parse_argv(pam_handle_t *handle,
int argc, const char **argv,
bool *create_session,
bool *kill_session,
- bool *kill_user) {
+ bool *kill_user,
+ char ***controllers,
+ char ***reset_controllers,
+ char ***kill_only_users,
+ char ***kill_exclude_users) {
unsigned i;
+ bool reset_controller_set = false;
+ bool kill_exclude_users_set = false;
assert(argc >= 0);
assert(argc == 0 || argv);
if (create_session)
*create_session = k;
+
} else if (startswith(argv[i], "kill-session=")) {
if ((k = parse_boolean(argv[i] + 13)) < 0) {
pam_syslog(handle, LOG_ERR, "Failed to parse kill-session= argument.");
if (kill_user)
*kill_user = k;
+
+ } else if (startswith(argv[i], "controllers=")) {
+
+ if (controllers) {
+ char **l;
+
+ if (!(l = strv_split(argv[i] + 12, ","))) {
+ pam_syslog(handle, LOG_ERR, "Out of memory.");
+ return -ENOMEM;
+ }
+
+ strv_free(*controllers);
+ *controllers = l;
+ }
+
+ } else if (startswith(argv[i], "reset-controllers=")) {
+
+ if (reset_controllers) {
+ char **l;
+
+ if (!(l = strv_split(argv[i] + 18, ","))) {
+ pam_syslog(handle, LOG_ERR, "Out of memory.");
+ return -ENOMEM;
+ }
+
+ strv_free(*reset_controllers);
+ *reset_controllers = l;
+ }
+
+ reset_controller_set = true;
+
+ } else if (startswith(argv[i], "kill-only-users=")) {
+
+ if (kill_only_users) {
+ char **l;
+
+ if (!(l = strv_split(argv[i] + 16, ","))) {
+ pam_syslog(handle, LOG_ERR, "Out of memory.");
+ return -ENOMEM;
+ }
+
+ strv_free(*kill_only_users);
+ *kill_only_users = l;
+ }
+
+ } else if (startswith(argv[i], "kill-exclude-users=")) {
+
+ if (kill_exclude_users) {
+ char **l;
+
+ if (!(l = strv_split(argv[i] + 19, ","))) {
+ pam_syslog(handle, LOG_ERR, "Out of memory.");
+ return -ENOMEM;
+ }
+
+ strv_free(*kill_exclude_users);
+ *kill_exclude_users = l;
+ }
+
+ kill_exclude_users_set = true;
+
} else {
pam_syslog(handle, LOG_ERR, "Unknown parameter '%s'.", argv[i]);
return -EINVAL;
}
}
+ if (!reset_controller_set && reset_controllers) {
+ char **l;
+
+ if (!(l = strv_new("cpu", NULL))) {
+ pam_syslog(handle, LOG_ERR, "Out of memory");
+ return -ENOMEM;
+ }
+
+ *reset_controllers = l;
+ }
+
+ if (controllers)
+ strv_remove(*controllers, "name=systemd");
+
+ if (reset_controllers)
+ strv_remove(*reset_controllers, "name=systemd");
+
if (kill_session && *kill_session && kill_user)
*kill_user = true;
+ if (!kill_exclude_users_set && kill_exclude_users) {
+ char **l;
+
+ if (!(l = strv_new("root", NULL))) {
+ pam_syslog(handle, LOG_ERR, "Out of memory");
+ return -ENOMEM;
+ }
+
+ *kill_exclude_users = l;
+ }
+
return 0;
}
if ((fd = open(fn, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_CREAT, 0600)) < 0)
return -errno;
- if (flock(fd, LOCK_EX) < 0)
- return -errno;
+ /* The BSD socket semantics are a lot nicer than those of
+ * POSIX locks. Which is why we use flock() here. BSD locking
+ * does not work across NFS which however is not needed here
+ * as the filesystems in question should be local, and only
+ * locally accessible, and most likely even tmpfs. */
+
+ if (flock(fd, LOCK_EX) < 0) {
+ int r = -errno;
+
+ close_nointr_nofail(fd);
+ return r;
+ }
return fd;
}
-static uint64_t get_session_id(void) {
+enum {
+ SESSION_ID_AUDIT = 'a',
+ SESSION_ID_COUNTER = 'c',
+ SESSION_ID_RANDOM = 'r'
+};
+
+static uint64_t get_session_id(int *mode) {
char *s;
int fd;
+ assert(mode);
+
/* First attempt: let's use the session ID of the audit
* system, if it is available. */
if (read_one_line_file("/proc/self/sessionid", &s) >= 0) {
r = safe_atou32(s, &u);
free(s);
- if (r >= 0 && u != (uint32_t) -1)
+ if (r >= 0 && u != (uint32_t) -1 && u > 0) {
+ *mode = SESSION_ID_AUDIT;
return (uint64_t) u;
+ }
}
/* Second attempt, use our own counter. */
close_nointr_nofail(fd);
- if (r >= 0)
+ if (r >= 0) {
+ *mode = SESSION_ID_COUNTER;
return counter;
+ }
}
+ *mode = SESSION_ID_RANDOM;
+
/* Last attempt, pick a random value */
return (uint64_t) random_ull();
}
const char **ret_username,
struct passwd **ret_pw) {
- const char *username;
- struct passwd *pw;
+ const char *username = NULL;
+ struct passwd *pw = NULL;
int r;
+ bool have_loginuid = false;
+ char *s;
assert(handle);
assert(ret_username);
assert(ret_pw);
- if ((r = pam_get_user(handle, &username, NULL)) != PAM_SUCCESS) {
- pam_syslog(handle, LOG_ERR, "Failed to get user name.");
- return r;
+ if (read_one_line_file("/proc/self/loginuid", &s) >= 0) {
+ uint32_t u;
+
+ r = safe_atou32(s, &u);
+ free(s);
+
+ if (r >= 0 && u != (uint32_t) -1 && u > 0) {
+ have_loginuid = true;
+ pw = pam_modutil_getpwuid(handle, u);
+ }
}
- if (!username || !*username) {
- pam_syslog(handle, LOG_ERR, "User name not valid.");
- return PAM_AUTH_ERR;
+ if (!have_loginuid) {
+ if ((r = pam_get_user(handle, &username, NULL)) != PAM_SUCCESS) {
+ pam_syslog(handle, LOG_ERR, "Failed to get user name.");
+ return r;
+ }
+
+ if (!username || !*username) {
+ pam_syslog(handle, LOG_ERR, "User name not valid.");
+ return PAM_AUTH_ERR;
+ }
+
+ pw = pam_modutil_getpwnam(handle, username);
}
- if (!(pw = pam_modutil_getpwnam(handle, username))) {
+ if (!pw) {
pam_syslog(handle, LOG_ERR, "Failed to get user data.");
return PAM_USER_UNKNOWN;
}
*ret_pw = pw;
- *ret_username = username;
+ *ret_username = username ? username : pw->pw_name;
return PAM_SUCCESS;
}
-static int create_user_group(pam_handle_t *handle, const char *group, struct passwd *pw, bool attach) {
+static int create_user_group(
+ pam_handle_t *handle,
+ const char *controller,
+ const char *group,
+ struct passwd *pw,
+ bool attach,
+ bool remember) {
+
int r;
assert(handle);
assert(group);
if (attach)
- r = cg_create_and_attach("name=systemd", group, 0);
+ r = cg_create_and_attach(controller, group, 0);
else
- r = cg_create("name=systemd", group);
+ r = cg_create(controller, group);
if (r < 0) {
pam_syslog(handle, LOG_ERR, "Failed to create cgroup: %s", strerror(-r));
return PAM_SESSION_ERR;
}
- if ((r = cg_set_task_access("name=systemd", group, 0755, pw->pw_uid, pw->pw_gid)) < 0 ||
- (r = cg_set_group_access("name=systemd", group, 0755, pw->pw_uid, pw->pw_gid)) < 0) {
+ if (r > 0 && remember) {
+ /* Remember that it was us who created this group, and
+ * that hence we need to remove it too. This is a
+ * protection against removing the cgroup when run
+ * recursively. */
+ if ((r = pam_set_data(handle, "systemd.created", INT_TO_PTR(1), NULL)) != PAM_SUCCESS) {
+ pam_syslog(handle, LOG_ERR, "Failed to install created variable.");
+ return r;
+ }
+ }
+
+ if ((r = cg_set_task_access(controller, group, 0644, pw->pw_uid, pw->pw_gid)) < 0 ||
+ (r = cg_set_group_access(controller, group, 0755, pw->pw_uid, pw->pw_gid)) < 0) {
pam_syslog(handle, LOG_ERR, "Failed to change access modes: %s", strerror(-r));
return PAM_SESSION_ERR;
}
return PAM_SUCCESS;
}
+static int reset_group(
+ pam_handle_t *handle,
+ const char *controller) {
+
+ int r;
+
+ assert(handle);
+
+ if ((r = cg_attach(controller, "/", 0)) < 0) {
+ pam_syslog(handle, LOG_ERR, "Failed to reset cgroup for controller %s: %s", controller, strerror(-r));
+ return PAM_SESSION_ERR;
+ }
+
+ return PAM_SUCCESS;
+}
+
_public_ PAM_EXTERN int pam_sm_open_session(
pam_handle_t *handle,
int flags,
char *buf = NULL;
int lock_fd = -1;
bool create_session = true;
+ char **controllers = NULL, **reset_controllers = NULL, **c;
assert(handle);
- pam_syslog(handle, LOG_INFO, "pam-systemd initializing");
-
- if (parse_argv(handle, argc, argv, &create_session, NULL, NULL) < 0)
- return PAM_SESSION_ERR;
+ /* pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing"); */
/* Make this a NOP on non-systemd systems */
if (sd_booted() <= 0)
return PAM_SUCCESS;
- if ((r = cgroup_init()) != 0) {
- pam_syslog(handle, LOG_ERR, "libcgroup initialization failed: %s", cgroup_strerror(r));
- r = PAM_SESSION_ERR;
- goto finish;
- }
+ if (parse_argv(handle,
+ argc, argv,
+ &create_session, NULL, NULL,
+ &controllers, &reset_controllers,
+ NULL, NULL) < 0)
+ return PAM_SESSION_ERR;
if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
goto finish;
/* Reuse or create XDG session ID */
if (!(id = pam_getenv(handle, "XDG_SESSION_ID"))) {
+ int mode;
- if (asprintf(&buf, "%llu", (unsigned long long) get_session_id()) < 0) {
+ if (asprintf(&buf, "%llux", (unsigned long long) get_session_id(&mode)) < 0) {
r = PAM_BUF_ERR;
goto finish;
}
+ /* To avoid id clashes we add the session id
+ * source to our session ids. Note that the
+ * session id source might change during
+ * runtime, because a filesystem became
+ * writable or the system reconfigured. */
+ buf[strlen(buf)-1] =
+ mode != SESSION_ID_AUDIT ? (char) mode : 0;
+
if ((r = pam_misc_setenv(handle, "XDG_SESSION_ID", buf, 0)) != PAM_SUCCESS) {
pam_syslog(handle, LOG_ERR, "Failed to set session id.");
goto finish;
r = asprintf(&buf, "/user/%s/%s", username, id);
} else
- r = asprintf(&buf, "/user/%s/no-session", username);
+ r = asprintf(&buf, "/user/%s/master", username);
if (r < 0) {
r = PAM_BUF_ERR;
goto finish;
}
- if ((r = create_user_group(handle, buf, pw, true)) != PAM_SUCCESS)
+ pam_syslog(handle, LOG_INFO, "Moving new user session for %s into control group %s.", username, buf);
+
+ if ((r = create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, buf, pw, true, true)) != PAM_SUCCESS)
goto finish;
+ /* The additional controllers don't really matter, so we
+ * ignore the return value */
+ STRV_FOREACH(c, controllers)
+ create_user_group(handle, *c, buf, pw, true, false);
+
+ STRV_FOREACH(c, reset_controllers)
+ reset_group(handle, *c);
+
r = PAM_SUCCESS;
finish:
if (lock_fd >= 0)
close_nointr_nofail(lock_fd);
+ strv_free(controllers);
+ strv_free(reset_controllers);
+
return r;
}
static int session_remains(pam_handle_t *handle, const char *user_path) {
- struct cgroup_file_info info;
- int level = 0, r;
- void *iterator = NULL;
+ int r;
bool remains = false;
+ DIR *d;
+ char *subgroup;
- zero(info);
+ if ((r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, user_path, &d)) < 0)
+ return r;
- r = cgroup_walk_tree_begin("name=systemd", user_path, 0, &iterator, &info, &level);
- while (r == 0) {
+ while ((r = cg_read_subgroup(d, &subgroup)) > 0) {
- if (info.type != CGROUP_FILE_TYPE_DIR)
- goto next;
+ remains = !streq(subgroup, "master");
+ free(subgroup);
- if (streq(info.path, ""))
- goto next;
+ if (remains)
+ break;
+ }
- if (streq(info.path, "no-session"))
- goto next;
+ closedir(d);
- remains = true;
- break;
+ if (r < 0)
+ return r;
- next:
+ return !!remains;
+}
- r = cgroup_walk_tree_next(0, &iterator, &info, level);
+static bool check_user_lists(
+ pam_handle_t *handle,
+ uid_t uid,
+ char **kill_only_users,
+ char **kill_exclude_users) {
+
+ const char *name = NULL;
+ char **l;
+
+ assert(handle);
+
+ if (uid == 0)
+ name = "root"; /* Avoid obvious NSS requests, to suppress network traffic */
+ else {
+ struct passwd *pw;
+
+ if ((pw = pam_modutil_getpwuid(handle, uid)))
+ name = pw->pw_name;
}
+ STRV_FOREACH(l, kill_exclude_users) {
+ uint32_t id;
- if (remains)
- r = 1;
- else if (r == 0 || r == ECGEOF)
- r = 0;
- else
- r = cg_translate_error(r, errno);
+ if (safe_atou32(*l, &id) >= 0)
+ if ((uid_t) id == uid)
+ return false;
- assert_se(cgroup_walk_tree_end(&iterator) == 0);
+ if (name && streq(name, *l))
+ return false;
+ }
- return r;
+ if (strv_isempty(kill_only_users))
+ return true;
+
+ STRV_FOREACH(l, kill_only_users) {
+ uint32_t id;
+
+ if (safe_atou32(*l, &id) >= 0)
+ if ((uid_t) id == uid)
+ return true;
+
+ if (name && streq(name, *l))
+ return true;
+ }
+
+ return false;
}
_public_ PAM_EXTERN int pam_sm_close_session(
char *session_path = NULL, *nosession_path = NULL, *user_path = NULL;
const char *id;
struct passwd *pw;
+ const void *created = NULL;
+ char **controllers = NULL, **c, **kill_only_users = NULL, **kill_exclude_users = NULL;
assert(handle);
- if (parse_argv(handle, argc, argv, NULL, &kill_session, &kill_user) < 0)
- return PAM_SESSION_ERR;
-
/* Make this a NOP on non-systemd systems */
if (sd_booted() <= 0)
return PAM_SUCCESS;
+ if (parse_argv(handle,
+ argc, argv,
+ NULL, &kill_session, &kill_user,
+ &controllers, NULL,
+ &kill_only_users, &kill_exclude_users) < 0)
+ return PAM_SESSION_ERR;
+
if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
goto finish;
goto finish;
}
+ /* We are probably still in some session/user dir. Move ourselves out of the way as first step */
+ if ((r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, "/user", 0)) < 0)
+ pam_syslog(handle, LOG_ERR, "Failed to move us away: %s", strerror(-r));
+
+ STRV_FOREACH(c, controllers)
+ if ((r = cg_attach(*c, "/user", 0)) < 0)
+ pam_syslog(handle, LOG_ERR, "Failed to move us away in %s hierarchy: %s", *c, strerror(-r));
+
if (asprintf(&user_path, "/user/%s", username) < 0) {
r = PAM_BUF_ERR;
goto finish;
}
- if ((id = pam_getenv(handle, "XDG_SESSION_ID"))) {
+ pam_get_data(handle, "systemd.created", &created);
+
+ if ((id = pam_getenv(handle, "XDG_SESSION_ID")) && created) {
if (asprintf(&session_path, "/user/%s/%s", username, id) < 0 ||
- asprintf(&nosession_path, "/user/%s/no-session", username) < 0) {
+ asprintf(&nosession_path, "/user/%s/master", username) < 0) {
r = PAM_BUF_ERR;
goto finish;
}
- if (kill_session) {
- /* Kill processes in session cgroup */
- if ((r = cg_kill_recursive_and_wait("name=systemd", session_path)) < 0)
+ if (kill_session && check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users)) {
+ pam_syslog(handle, LOG_INFO, "Killing remaining processes of user session %s of %s.", id, username);
+
+ /* Kill processes in session cgroup, and delete it */
+ if ((r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, session_path, true)) < 0)
pam_syslog(handle, LOG_ERR, "Failed to kill session cgroup: %s", strerror(-r));
+ } else {
+ pam_syslog(handle, LOG_INFO, "Moving remaining processes of user session %s of %s into control group %s.", id, username, nosession_path);
- } else {
- /* Migrate processes from session to
- * no-session cgroup. First, try to create the
- * no-session group in case it doesn't exist
- * yet. */
- create_user_group(handle, nosession_path, pw, 0);
+ /* Migrate processes from session to user
+ * cgroup. First, try to create the user group
+ * in case it doesn't exist yet. Also, delete
+ * the session group. */
+ create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, nosession_path, pw, false, false);
- if ((r = cg_migrate_recursive("name=systemd", session_path, nosession_path, false)) < 0)
+ if ((r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, session_path, nosession_path, false, true)) < 0)
pam_syslog(handle, LOG_ERR, "Failed to migrate session cgroup: %s", strerror(-r));
}
- /* Delete session cgroup */
- if (r < 0)
- pam_syslog(handle, LOG_INFO, "Couldn't empty session cgroup, not deleting.");
- else {
- if ((r = cg_delete("name=systemd", session_path)) < 0)
- pam_syslog(handle, LOG_ERR, "Failed to delete session cgroup: %s", strerror(-r));
+ STRV_FOREACH(c, controllers) {
+ create_user_group(handle, *c, nosession_path, pw, false, false);
+
+ if ((r = cg_migrate_recursive(*c, session_path, nosession_path, false, true)) < 0)
+ pam_syslog(handle, LOG_ERR, "Failed to migrate session cgroup in hierarchy %s: %s", *c, strerror(-r));
}
}
/* GC user tree */
- cg_trim("name=systemd", user_path, false);
+ cg_trim(SYSTEMD_CGROUP_CONTROLLER, user_path, false);
if ((r = session_remains(handle, user_path)) < 0)
pam_syslog(handle, LOG_ERR, "Failed to determine whether a session remains: %s", strerror(-r));
/* Kill user processes not attached to any session */
- if (kill_user && r == 0) {
+ if (kill_user && r == 0 && check_user_lists(handle, pw->pw_uid, kill_only_users, kill_exclude_users)) {
- /* Kill no-session cgroup */
- if ((r = cg_kill_recursive_and_wait("name=systemd", user_path)) < 0)
+ /* Kill user cgroup */
+ if ((r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, user_path, true)) < 0)
pam_syslog(handle, LOG_ERR, "Failed to kill user cgroup: %s", strerror(-r));
} else {
- if ((r = cg_is_empty_recursive("name=systemd", user_path, true)) < 0)
+ if ((r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, user_path, true)) < 0)
pam_syslog(handle, LOG_ERR, "Failed to check user cgroup: %s", strerror(-r));
- /* If we managed to kill somebody, don't cleanup the cgroup. */
- if (r == 0)
+ /* Remove user cgroup */
+ if (r > 0) {
+ if ((r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, user_path)) < 0)
+ pam_syslog(handle, LOG_ERR, "Failed to delete user cgroup: %s", strerror(-r));
+
+ /* If we managed to find somebody, don't cleanup the cgroup. */
+ } else if (r == 0)
r = -EBUSY;
}
+ STRV_FOREACH(c, controllers)
+ cg_trim(*c, user_path, true);
+
if (r >= 0) {
const char *runtime_dir;
- /* Remove user cgroup */
- if ((r = cg_delete("name=systemd", user_path)) < 0)
- pam_syslog(handle, LOG_ERR, "Failed to delete user cgroup: %s", strerror(-r));
-
- /* This will migrate us to the /user cgroup. */
-
if ((runtime_dir = pam_getenv(handle, "XDG_RUNTIME_DIR")))
if ((r = rm_rf(runtime_dir, false, true)) < 0)
pam_syslog(handle, LOG_ERR, "Failed to remove runtime directory: %s", strerror(-r));
}
+ /* pam_syslog(handle, LOG_DEBUG, "pam-systemd done"); */
+
r = PAM_SUCCESS;
finish:
free(nosession_path);
free(user_path);
+ strv_free(controllers);
+ strv_free(kill_exclude_users);
+ strv_free(kill_only_users);
+
return r;
}
~ianmdlvl / elogind.git / blobdiff