pam: duplicate cgroup tree in the cpu hierarchy by default, optionally more

1 files changed, 81 insertions, 14 deletions

diff --git a/src/pam-module.c b/src/pam-module.c
index bc99684e11..54a7b451e8 100644
--- a/src/pam-module.c
+++ b/src/pam-module.c
@@ -35,14 +35,17 @@
 #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) {
 
         unsigned i;
+        bool controller_set = false;
 
         assert(argc >= 0);
         assert(argc == 0 || argv);
@@ -58,6 +61,7 @@ static int parse_argv(pam_handle_t *handle,
 
                         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.");
@@ -75,12 +79,43 @@ static int parse_argv(pam_handle_t *handle,
 
                         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;
+                        }
+
+                        controller_set = true;
+
                 } else {
                         pam_syslog(handle, LOG_ERR, "Unknown parameter '%s'.", argv[i]);
                         return -EINVAL;
                 }
         }
 
+        if (!controller_set && controllers) {
+                char **l;
+
+                if (!(l = strv_new("cpu", NULL))) {
+                        pam_syslog(handle, LOG_ERR, "Out of memory");
+                        return -ENOMEM;
+                }
+
+                *controllers = l;
+        }
+
+        if (controllers)
+                strv_remove(*controllers, "name=systemd");
+
         if (kill_session && *kill_session && kill_user)
                 *kill_user = true;
 
@@ -226,16 +261,23 @@ static int get_user_data(
         return PAM_SUCCESS;
 }
 
-static int create_user_group(pam_handle_t *handle, const char *group, struct passwd *pw, bool attach, bool remember) {
+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(SYSTEMD_CGROUP_CONTROLLER, group, 0);
+                r = cg_create_and_attach(controller, group, 0);
         else
-                r = cg_create(SYSTEMD_CGROUP_CONTROLLER, group);
+                r = cg_create(controller, group);
 
         if (r < 0) {
                 pam_syslog(handle, LOG_ERR, "Failed to create cgroup: %s", strerror(-r));
@@ -253,8 +295,8 @@ static int create_user_group(pam_handle_t *handle, const char *group, struct pas
                 }
         }
 
-        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) {
+        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;
         }
@@ -273,18 +315,19 @@ _public_ PAM_EXTERN int pam_sm_open_session(
         char *buf = NULL;
         int lock_fd = -1;
         bool create_session = true;
+        char **controllers = NULL, **c;
 
         assert(handle);
 
         /* pam_syslog(handle, LOG_DEBUG, "pam-systemd initializing"); */
 
-        if (parse_argv(handle, argc, argv, &create_session, NULL, NULL) < 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, &create_session, NULL, NULL, &controllers) < 0)
+                return PAM_SESSION_ERR;
+
         if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
                 goto finish;
 
@@ -362,9 +405,14 @@ _public_ PAM_EXTERN int pam_sm_open_session(
 
         pam_syslog(handle, LOG_INFO, "Moving new user session for %s into control group %s.", username, buf);
 
-        if ((r = create_user_group(handle, buf, pw, true, true)) != PAM_SUCCESS)
+        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);
+
         r = PAM_SUCCESS;
 
 finish:
@@ -373,6 +421,8 @@ finish:
         if (lock_fd >= 0)
                 close_nointr_nofail(lock_fd);
 
+        strv_free(controllers);
+
         return r;
 }
 
@@ -415,16 +465,17 @@ _public_ PAM_EXTERN int pam_sm_close_session(
         const char *id;
         struct passwd *pw;
         const void *created = NULL;
+        char **controllers = NULL, **c;
 
         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) < 0)
+                return PAM_SESSION_ERR;
+
         if ((r = get_user_data(handle, &username, &pw)) != PAM_SUCCESS)
                 goto finish;
 
@@ -438,6 +489,10 @@ _public_ PAM_EXTERN int pam_sm_close_session(
         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;
@@ -466,11 +521,18 @@ _public_ PAM_EXTERN int pam_sm_close_session(
                          * cgroup. First, try to create the user group
                          * in case it doesn't exist yet. Also, delete
                          * the session group. */
-                        create_user_group(handle, nosession_path, pw, false, false);
+                        create_user_group(handle, SYSTEMD_CGROUP_CONTROLLER, nosession_path, pw, false, false);
 
                         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));
                 }
+
+                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 */
@@ -500,6 +562,9 @@ _public_ PAM_EXTERN int pam_sm_close_session(
                         r = -EBUSY;
         }
 
+        STRV_FOREACH(c, controllers)
+                cg_trim(*c, user_path, true);
+
         if (r >= 0) {
                 const char *runtime_dir;
 
@@ -520,5 +585,7 @@ finish:
         free(nosession_path);
         free(user_path);
 
+        strv_free(controllers);
+
         return r;
 }