Commit 1f73f0f1 authored by Lennart Poettering's avatar Lennart Poettering
Browse files

pam: determine user cgroup tree from cgroup of PID 1

parent 04d391da
......@@ -967,3 +967,31 @@ int cg_fix_path(const char *path, char **result) {
return r;
}
int cg_get_user_path(char **path) {
char *root, *p;
assert(path);
/* Figure out the place to put user cgroups below. We use the
* same as PID 1 has but with the "/system" suffix replaced by
* "/user" */
if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 1, &root) < 0)
p = strdup("/user");
else {
if (endswith(root, "/system"))
root[strlen(root) - 7] = 0;
else if (streq(root, "/"))
root[0] = 0;
p = strappend(root, "/user");
free(root);
}
if (!p)
return -ENOMEM;
*path = p;
return 0;
}
......@@ -68,4 +68,6 @@ int cg_install_release_agent(const char *controller, const char *agent);
int cg_is_empty(const char *controller, const char *path, bool ignore_self);
int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self);
int cg_get_user_path(char **path);
#endif
......@@ -199,10 +199,8 @@ static int open_file_and_lock(const char *fn) {
* locally accessible, and most likely even tmpfs. */
if (flock(fd, LOCK_EX) < 0) {
int r = -errno;
close_nointr_nofail(fd);
return r;
return -errno;
}
return fd;
......@@ -275,6 +273,7 @@ static uint64_t get_session_id(int *mode) {
/* Last attempt, pick a random value */
return (uint64_t) random_ull();
}
static int get_user_data(
pam_handle_t *handle,
const char **ret_username,
......@@ -398,6 +397,7 @@ _public_ PAM_EXTERN int pam_sm_open_session(
int lock_fd = -1;
bool create_session = true;
char **controllers = NULL, **reset_controllers = NULL, **c;
char *cgroup_user_tree = NULL;
assert(handle);
......@@ -417,6 +417,12 @@ _public_ PAM_EXTERN int pam_sm_open_session(
if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
goto finish;
if ((r = cg_get_user_path(&cgroup_user_tree)) < 0) {
pam_syslog(handle, LOG_ERR, "Failed to determine user cgroup tree: %s", strerror(-r));
r = PAM_SYSTEM_ERR;
goto finish;
}
if (safe_mkdir(RUNTIME_DIR "/user", 0755, 0, 0) < 0) {
pam_syslog(handle, LOG_ERR, "Failed to create runtime directory: %m");
r = PAM_SYSTEM_ERR;
......@@ -480,9 +486,9 @@ _public_ PAM_EXTERN int pam_sm_open_session(
}
}
r = asprintf(&buf, "/user/%s/%s", username, id);
r = asprintf(&buf, "%s/%s/%s", cgroup_user_tree, username, id);
} else
r = asprintf(&buf, "/user/%s/master", username);
r = asprintf(&buf, "%s/%s/master", cgroup_user_tree, username);
if (r < 0) {
r = PAM_BUF_ERR;
......@@ -513,6 +519,8 @@ finish:
strv_free(controllers);
strv_free(reset_controllers);
free(cgroup_user_tree);
return r;
}
......@@ -604,6 +612,7 @@ _public_ PAM_EXTERN int pam_sm_close_session(
struct passwd *pw;
const void *created = NULL;
char **controllers = NULL, **c, **kill_only_users = NULL, **kill_exclude_users = NULL;
char *cgroup_user_tree = NULL;
assert(handle);
......@@ -621,6 +630,12 @@ _public_ PAM_EXTERN int pam_sm_close_session(
if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
goto finish;
if ((r = cg_get_user_path(&cgroup_user_tree)) < 0) {
pam_syslog(handle, LOG_ERR, "Failed to determine user cgroup tree: %s", strerror(-r));
r = PAM_SYSTEM_ERR;
goto finish;
}
if ((lock_fd = open_file_and_lock(RUNTIME_DIR "/user/.pam-systemd-lock")) < 0) {
pam_syslog(handle, LOG_ERR, "Failed to lock runtime directory: %m");
r = PAM_SYSTEM_ERR;
......@@ -628,14 +643,14 @@ _public_ PAM_EXTERN int pam_sm_close_session(
}
/* 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)
if ((r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, cgroup_user_tree, 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)
if ((r = cg_attach(*c, cgroup_user_tree, 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) {
if (asprintf(&user_path, "%s/%s", cgroup_user_tree, username) < 0) {
r = PAM_BUF_ERR;
goto finish;
}
......@@ -644,8 +659,8 @@ _public_ PAM_EXTERN int pam_sm_close_session(
if ((id = pam_getenv(handle, "XDG_SESSION_ID")) && created) {
if (asprintf(&session_path, "/user/%s/%s", username, id) < 0 ||
asprintf(&nosession_path, "/user/%s/master", username) < 0) {
if (asprintf(&session_path, "%s/%s/%s", cgroup_user_tree, username, id) < 0 ||
asprintf(&nosession_path, "%s/%s/master", cgroup_user_tree, username) < 0) {
r = PAM_BUF_ERR;
goto finish;
}
......@@ -731,5 +746,7 @@ finish:
strv_free(kill_exclude_users);
strv_free(kill_only_users);
free(cgroup_user_tree);
return r;
}
......@@ -57,14 +57,25 @@ int main(int argc, char*argv[]) {
} else if (streq(argv[1], "stop")) {
int r, q;
char *cgroup_user_tree = NULL;
if ((r = write_one_line_file("/var/run/nologin", "System is going down.")) < 0)
log_error("Failed to create /var/run/nologin: %s", strerror(-r));
if ((q = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, "/user", true)) < 0)
if ((q = cg_get_user_path(&cgroup_user_tree)) < 0) {
log_error("Failed to determine use path: %s", strerror(-q));
goto finish;
}
q = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, cgroup_user_tree, true);
free(cgroup_user_tree);
if (q < 0) {
log_error("Failed to kill sessions: %s", strerror(-q));
goto finish;
}
if (r < 0 || q < 0)
if (r < 0)
goto finish;
} else {
......
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