#include <security/pam_ext.h>
#include <security/pam_misc.h>
-#include <libcgroup.h>
-
#include "util.h"
#include "cgroup-util.h"
#include "macro.h"
if ((fd = open(fn, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_CREAT, 0600)) < 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)
return -errno;
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) {
+ *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();
}
assert(group);
if (attach)
- r = cg_create_and_attach("name=systemd", group, 0);
+ r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, group, 0);
else
- r = cg_create("name=systemd", group);
+ r = cg_create(SYSTEMD_CGROUP_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 = cg_set_task_access(SYSTEMD_CGROUP_CONTROLLER, group, 0755, pw->pw_uid, pw->pw_gid)) < 0 ||
+ (r = cg_set_group_access(SYSTEMD_CGROUP_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;
}
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 ((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;
}
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);
-
- r = cgroup_walk_tree_begin("name=systemd", user_path, 0, &iterator, &info, &level);
- while (r == 0) {
-
- if (info.type != CGROUP_FILE_TYPE_DIR)
- goto next;
-
- if (streq(info.path, ""))
- goto next;
-
- if (streq(info.path, "no-session"))
- goto next;
+ if ((r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, user_path, &d)) < 0)
+ return r;
- remains = true;
- break;
+ while ((r = cg_read_subgroup(d, &subgroup)) > 0) {
- next:
+ remains = !streq(subgroup, "no-session");
+ free(subgroup);
- r = cgroup_walk_tree_next(0, &iterator, &info, level);
+ if (remains)
+ break;
}
+ closedir(d);
- if (remains)
- r = 1;
- else if (r == 0 || r == ECGEOF)
- r = 0;
- else
- r = cg_translate_error(r, errno);
-
- assert_se(cgroup_walk_tree_end(&iterator) == 0);
+ if (r < 0)
+ return r;
- return r;
+ return !!remains;
}
_public_ PAM_EXTERN int pam_sm_close_session(
goto finish;
}
+ /* We are probably still in some session/no-session 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));
+
if (asprintf(&user_path, "/user/%s", 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)
+ /* 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 {
+ } else {
/* Migrate processes from session to
* no-session cgroup. First, try to create the
* no-session group in case it doesn't exist
- * yet. */
+ * yet. Also, delete the session group. */
create_user_group(handle, nosession_path, pw, 0);
- 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));
- }
}
/* 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));
if (kill_user && r == 0) {
/* Kill no-session cgroup */
- if ((r = cg_kill_recursive_and_wait("name=systemd", user_path)) < 0)
+ 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;
}
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")))
~ianmdlvl / elogind.git / blobdiff