chiark / gitweb /
Prep v231: Move elogind specific code in login/logind.c to login/elogind.c
authorSven Eden <yamakuzure@gmx.net>
Wed, 14 Jun 2017 15:39:24 +0000 (17:39 +0200)
committerSven Eden <yamakuzure@gmx.net>
Fri, 16 Jun 2017 08:13:01 +0000 (10:13 +0200)
src/login/elogind.c [new file with mode: 0644]
src/login/elogind.h [new file with mode: 0644]
src/login/logind.c
src/login/logind.conf.in
src/login/logind.h

diff --git a/src/login/elogind.c b/src/login/elogind.c
new file mode 100644 (file)
index 0000000..e76654b
--- /dev/null
@@ -0,0 +1,311 @@
+/***
+  This file is part of elogind.
+
+  Copyright 2017 Sven Eden
+
+  elogind is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  elogind is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with elogind; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+
+#include "bus-util.h"
+#include "cgroup.h"
+#include "elogind.h"
+#include "fd-util.h"
+#include "mount-setup.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "umask-util.h"
+
+
+#define CGROUPS_AGENT_RCVBUF_SIZE (8*1024*1024)
+
+
+static int signal_agent_released(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
+        Manager *m = userdata;
+        const char *cgroup;
+        uid_t sender_uid;
+        int r;
+
+        assert(message);
+        assert(m);
+
+        /* only accept org.freedesktop.elogind.Agent from UID=0 */
+        r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_get_euid(creds, &sender_uid);
+        if (r < 0 || sender_uid != 0)
+                return 0;
+
+        /* parse 'cgroup-empty' notification */
+        r = sd_bus_message_read(message, "s", &cgroup);
+        if (r < 0) {
+                bus_log_parse_error(r);
+                return 0;
+        }
+
+        manager_notify_cgroup_empty(m, cgroup);
+
+        return 0;
+}
+
+/// Add-On for manager_connect_bus()
+void elogind_bus_setup_system(Manager* m) {
+        int r;
+
+        assert(m);
+        assert(m->bus);
+
+        /* if we are a user instance we get the Released message via the system bus */
+        if (MANAGER_IS_USER(m)) {
+                r = sd_bus_add_match(
+                                m->bus,
+                                NULL,
+                                "type='signal',"
+                                "interface='org.freedesktop.elogind.Agent',"
+                                "member='Released',"
+                                "path='/org/freedesktop/elogind/agent'",
+                                signal_agent_released, m);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to register Released match on system bus: %m");
+        }
+
+        log_debug("Successfully connected to system bus.");
+}
+
+static int bus_forward_agent_released(Manager *m, const char *path) {
+        int r;
+
+        assert(m);
+        assert(path);
+
+        if (!MANAGER_IS_SYSTEM(m))
+                return 0;
+
+        if (!m->bus)
+                return 0;
+
+        /* If we are running a system instance we forward the agent message on the system bus, so that the user
+         * instances get notified about this, too */
+
+        r = sd_bus_emit_signal(m->bus,
+                               "/org/freedesktop/elogind/agent",
+                               "org.freedesktop.elogind.Agent",
+                               "Released",
+                               "s", path);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to propagate agent release message: %m");
+
+        return 1;
+}
+
+static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+        Manager *m = userdata;
+        char buf[PATH_MAX+1];
+        ssize_t n;
+
+        n = recv(fd, buf, sizeof(buf), 0);
+        if (n < 0)
+                return log_error_errno(errno, "Failed to read cgroups agent message: %m");
+        if (n == 0) {
+                log_error("Got zero-length cgroups agent message, ignoring.");
+                return 0;
+        }
+        if ((size_t) n >= sizeof(buf)) {
+                log_error("Got overly long cgroups agent message, ignoring.");
+                return 0;
+        }
+
+        if (memchr(buf, 0, n)) {
+                log_error("Got cgroups agent message with embedded NUL byte, ignoring.");
+                return 0;
+        }
+        buf[n] = 0;
+
+        manager_notify_cgroup_empty(m, buf);
+        bus_forward_agent_released(m, buf);
+
+        return 0;
+}
+
+/// Add-On for manager_connect_bus()
+int elogind_setup_cgroups_agent(Manager *m) {
+
+        static const union sockaddr_union sa = {
+                .un.sun_family = AF_UNIX,
+                .un.sun_path = "/run/systemd/cgroups-agent",
+        };
+        int r;
+
+        /* This creates a listening socket we receive cgroups agent messages on. We do not use D-Bus for delivering
+         * these messages from the cgroups agent binary to PID 1, as the cgroups agent binary is very short-living, and
+         * each instance of it needs a new D-Bus connection. Since D-Bus connections are SOCK_STREAM/AF_UNIX, on
+         * overloaded systems the backlog of the D-Bus socket becomes relevant, as not more than the configured number
+         * of D-Bus connections may be queued until the kernel will start dropping further incoming connections,
+         * possibly resulting in lost cgroups agent messages. To avoid this, we'll use a private SOCK_DGRAM/AF_UNIX
+         * socket, where no backlog is relevant as communication may take place without an actual connect() cycle, and
+         * we thus won't lose messages.
+         *
+         * Note that PID 1 will forward the agent message to system bus, so that the user systemd instance may listen
+         * to it. The system instance hence listens on this special socket, but the user instances listen on the system
+         * bus for these messages. */
+
+        if (m->test_run)
+                return 0;
+
+        if (!MANAGER_IS_SYSTEM(m))
+                return 0;
+
+        if (cg_unified() > 0) /* We don't need this anymore on the unified hierarchy */
+                return 0;
+
+        if (m->cgroups_agent_fd < 0) {
+                _cleanup_close_ int fd = -1;
+
+                /* First free all secondary fields */
+                m->cgroups_agent_event_source = sd_event_source_unref(m->cgroups_agent_event_source);
+
+                fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+                if (fd < 0)
+                        return log_error_errno(errno, "Failed to allocate cgroups agent socket: %m");
+
+                fd_inc_rcvbuf(fd, CGROUPS_AGENT_RCVBUF_SIZE);
+
+                (void) unlink(sa.un.sun_path);
+
+                /* Only allow root to connect to this socket */
+                RUN_WITH_UMASK(0077)
+                        r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
+                if (r < 0)
+                        return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
+
+                m->cgroups_agent_fd = fd;
+                fd = -1;
+        }
+
+        if (!m->cgroups_agent_event_source) {
+                r = sd_event_add_io(m->event, &m->cgroups_agent_event_source, m->cgroups_agent_fd, EPOLLIN, manager_dispatch_cgroups_agent_fd, m);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to allocate cgroups agent event source: %m");
+
+                /* Process cgroups notifications early, but after having processed service notification messages or
+                 * SIGCHLD signals, so that a cgroup running empty is always just the last safety net of notification,
+                 * and we collected the metadata the notification and SIGCHLD stuff offers first. Also see handling of
+                 * cgroup inotify for the unified cgroup stuff. */
+                r = sd_event_source_set_priority(m->cgroups_agent_event_source, SD_EVENT_PRIORITY_NORMAL-5);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to set priority of cgroups agent event source: %m");
+
+                (void) sd_event_source_set_description(m->cgroups_agent_event_source, "manager-cgroups-agent");
+        }
+
+        return 0;
+}
+
+/// Add-On for manager_free()
+void elogind_manager_free(Manager* m) {
+
+        manager_shutdown_cgroup(m, true);
+
+        sd_event_source_unref(m->cgroups_agent_event_source);
+
+        safe_close(m->cgroups_agent_fd);
+
+        strv_free(m->suspend_mode);
+        strv_free(m->suspend_state);
+        strv_free(m->hibernate_mode);
+        strv_free(m->hibernate_state);
+        strv_free(m->hybrid_sleep_mode);
+        strv_free(m->hybrid_sleep_state);
+}
+
+/// Add-On for manager_new()
+int elogind_manager_new(Manager* m) {
+        int r = 0;
+
+        m->cgroups_agent_fd = -1;
+        m->pin_cgroupfs_fd  = -1;
+        m->test_run         = false;
+
+        /* Init sleep modes and states */
+        m->suspend_mode       = NULL;
+        m->suspend_state      = NULL;
+        m->hibernate_mode     = NULL;
+        m->hibernate_state    = NULL;
+        m->hybrid_sleep_mode  = NULL;
+        m->hybrid_sleep_state = NULL;
+
+        /* If elogind should be its own controller, mount its cgroup */
+        if (streq(SYSTEMD_CGROUP_CONTROLLER, "name=elogind")) {
+                m->is_system = true;
+                r = mount_setup(true);
+        } else
+                m->is_system = false;
+
+        /* Make cgroups */
+        if (r > -1)
+                r = manager_setup_cgroup(m);
+
+        return r;
+}
+
+/// Add-On for manager_reset_config()
+void elogind_manager_reset_config(Manager* m) {
+
+#ifdef ENABLE_DEBUG_ELOGIND
+        int dbg_cnt;
+#endif // ENABLE_DEBUG_ELOGIND
+
+        /* Set default Sleep config if not already set by logind.conf */
+        if (!m->suspend_state)
+                m->suspend_state = strv_new("mem", "standby", "freeze", NULL);
+        if (!m->hibernate_mode)
+                m->hibernate_mode = strv_new("platform", "shutdown", NULL);
+        if (!m->hibernate_state)
+                m->hibernate_state = strv_new("disk", NULL);
+        if (!m->hybrid_sleep_mode)
+                m->hybrid_sleep_mode = strv_new("suspend", "platform", "shutdown", NULL);
+        if (!m->hybrid_sleep_state)
+                m->hybrid_sleep_state = strv_new("disk", NULL);
+
+#ifdef ENABLE_DEBUG_ELOGIND
+        dbg_cnt = -1;
+        while (m->suspend_mode && m->suspend_mode[++dbg_cnt])
+                log_debug_elogind("suspend_mode[%d] = %s",
+                                  dbg_cnt, m->suspend_mode[dbg_cnt]);
+        dbg_cnt = -1;
+        while (m->suspend_state[++dbg_cnt])
+                log_debug_elogind("suspend_state[%d] = %s",
+                                  dbg_cnt, m->suspend_state[dbg_cnt]);
+        dbg_cnt = -1;
+        while (m->hibernate_mode[++dbg_cnt])
+                log_debug_elogind("hibernate_mode[%d] = %s",
+                                  dbg_cnt, m->hibernate_mode[dbg_cnt]);
+        dbg_cnt = -1;
+        while (m->hibernate_state[++dbg_cnt])
+                log_debug_elogind("hibernate_state[%d] = %s",
+                                  dbg_cnt, m->hibernate_state[dbg_cnt]);
+        dbg_cnt = -1;
+        while (m->hybrid_sleep_mode[++dbg_cnt])
+                log_debug_elogind("hybrid_sleep_mode[%d] = %s",
+                                  dbg_cnt, m->hybrid_sleep_mode[dbg_cnt]);
+        dbg_cnt = -1;
+        while (m->hybrid_sleep_state[++dbg_cnt])
+                log_debug_elogind("hybrid_sleep_state[%d] = %s",
+                                  dbg_cnt, m->hybrid_sleep_state[dbg_cnt]);
+#endif // ENABLE_DEBUG_ELOGIND
+}
diff --git a/src/login/elogind.h b/src/login/elogind.h
new file mode 100644 (file)
index 0000000..155654b
--- /dev/null
@@ -0,0 +1,43 @@
+#pragma once
+#ifndef ELOGIND_SRC_LOGIN_ELOGIN_H_INCLUDED
+#define ELOGIND_SRC_LOGIN_ELOGIN_H_INCLUDED
+
+/***
+  This file is part of elogind.
+
+  Copyright 2017 Sven Eden
+
+  elogind is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  elogind is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with elogind; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+
+#include "logind.h"
+#include "sd-bus.h"
+
+
+/// Add-Ons for manager_connect_bus()
+void elogind_bus_setup_system(Manager* m);
+int  elogind_setup_cgroups_agent(Manager *m);
+
+/// Add-On for manager_free()
+void elogind_manager_free(Manager* m);
+
+/// Add-On for manager_new()
+int elogind_manager_new(Manager* m);
+
+/// Add-On for manager_reset_config()
+void elogind_manager_reset_config(Manager* m);
+
+
+#endif // ELOGIND_SRC_LOGIN_ELOGIN_H_INCLUDED
index b976981..e0f391f 100644 (file)
 #include "strv.h"
 #include "udev-util.h"
 
-/// additional includes elogind needs
+/// Additional includes needed by elogind
 #include "cgroup.h"       // From src/core/
+#include "elogind.h"
 #include "label.h"
-#include "mount-setup.h"  // From src/core
 #include "musl_missing.h"
 
 static void manager_free(Manager *m);
 
 static void manager_reset_config(Manager *m) {
 
-#ifdef ENABLE_DEBUG_ELOGIND
-        int dbg_cnt;
-#endif // ENABLE_DEBUG_ELOGIND
-
 #if 0 /// elogind does not support autospawning of vts
         m->n_autovts = 6;
         m->reserve_vt = 6;
@@ -88,44 +84,9 @@ static void manager_reset_config(Manager *m) {
         m->kill_only_users = strv_free(m->kill_only_users);
         m->kill_exclude_users = strv_free(m->kill_exclude_users);
 
-        /* Set default Sleep config if not already set by logind.conf */
-        if (!m->suspend_state)
-                m->suspend_state = strv_new("mem", "standby", "freeze", NULL);
-        if (!m->hibernate_mode)
-                m->hibernate_mode = strv_new("platform", "shutdown", NULL);
-        if (!m->hibernate_state)
-                m->hibernate_state = strv_new("disk", NULL);
-        if (!m->hybrid_sleep_mode)
-                m->hybrid_sleep_mode = strv_new("suspend", "platform", "shutdown", NULL);
-        if (!m->hybrid_sleep_state)
-                m->hybrid_sleep_state = strv_new("disk", NULL);
-
-#ifdef ENABLE_DEBUG_ELOGIND
-        dbg_cnt = -1;
-        while (m->suspend_mode && m->suspend_mode[++dbg_cnt])
-                log_debug_elogind("suspend_mode[%d] = %s",
-                                  dbg_cnt, m->suspend_mode[dbg_cnt]);
-        dbg_cnt = -1;
-        while (m->suspend_state[++dbg_cnt])
-                log_debug_elogind("suspend_state[%d] = %s",
-                                  dbg_cnt, m->suspend_state[dbg_cnt]);
-        dbg_cnt = -1;
-        while (m->hibernate_mode[++dbg_cnt])
-                log_debug_elogind("hibernate_mode[%d] = %s",
-                                  dbg_cnt, m->hibernate_mode[dbg_cnt]);
-        dbg_cnt = -1;
-        while (m->hibernate_state[++dbg_cnt])
-                log_debug_elogind("hibernate_state[%d] = %s",
-                                  dbg_cnt, m->hibernate_state[dbg_cnt]);
-        dbg_cnt = -1;
-        while (m->hybrid_sleep_mode[++dbg_cnt])
-                log_debug_elogind("hybrid_sleep_mode[%d] = %s",
-                                  dbg_cnt, m->hybrid_sleep_mode[dbg_cnt]);
-        dbg_cnt = -1;
-        while (m->hybrid_sleep_state[++dbg_cnt])
-                log_debug_elogind("hybrid_sleep_state[%d] = %s",
-                                  dbg_cnt, m->hybrid_sleep_state[dbg_cnt]);
-#endif // ENABLE_DEBUG_ELOGIND
+#if 1 /// elogind needs an Add-On for sleep configuration
+        elogind_manager_reset_config(m);
+#endif // 1
 }
 
 static Manager *manager_new(void) {
@@ -136,7 +97,6 @@ static Manager *manager_new(void) {
         if (!m)
                 return NULL;
 
-        m->pin_cgroupfs_fd = -1;
         m->console_active_fd = -1;
 #if 0 /// UNNEEDED by elogind
         m->reserve_vt_fd = -1;
@@ -154,29 +114,14 @@ static Manager *manager_new(void) {
         m->user_units = hashmap_new(&string_hash_ops);
         m->session_units = hashmap_new(&string_hash_ops);
 
-        m->test_run   = false;
-
         if (!m->devices || !m->seats || !m->sessions || !m->users || !m->inhibitors || !m->buttons || !m->user_units || !m->session_units)
                 goto fail;
 
-        /* If elogind should be its own controller, mount its cgroup */
-        if (streq(SYSTEMD_CGROUP_CONTROLLER, "name=elogind")) {
-                r = mount_setup(true);
-                if (r < 0)
-                        goto fail;
-        }
-
-        /* Make cgroups */
-        r = manager_setup_cgroup(m);
+#if 1 /// elogind needs some more data
+        r = elogind_manager_new(m);
         if (r < 0)
                 goto fail;
-
-        m->suspend_mode       = NULL;
-        m->suspend_state      = NULL;
-        m->hibernate_mode     = NULL;
-        m->hibernate_state    = NULL;
-        m->hybrid_sleep_mode  = NULL;
-        m->hybrid_sleep_state = NULL;
+#endif // 1
 
         m->udev = udev_new();
         if (!m->udev)
@@ -269,7 +214,9 @@ static void manager_free(Manager *m) {
         safe_close(m->reserve_vt_fd);
 #endif // 0
 
-        manager_shutdown_cgroup(m, true);
+#if 1 /// elogind has to free its own data
+        elogind_manager_free(m);
+#endif // 1
 
         strv_free(m->kill_only_users);
         strv_free(m->kill_exclude_users);
@@ -277,14 +224,6 @@ static void manager_free(Manager *m) {
         free(m->scheduled_shutdown_type);
         free(m->scheduled_shutdown_tty);
         free(m->wall_message);
-
-        strv_free(m->suspend_mode);
-        strv_free(m->suspend_state);
-        strv_free(m->hibernate_mode);
-        strv_free(m->hibernate_state);
-        strv_free(m->hybrid_sleep_mode);
-        strv_free(m->hybrid_sleep_state);
-
 #if 0 /// UNNEEDED by elogind
         free(m->action_job);
 #endif // 0
@@ -687,46 +626,6 @@ static int manager_reserve_vt(Manager *m) {
 }
 #endif // 0
 
-static int signal_agent_released(sd_bus_message *message, void *userdata, sd_bus_error *error) {
-        _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
-        Manager *m = userdata;
-        const char *cgroup;
-        Session *s;
-        uid_t sender_uid;
-        int r;
-
-        assert(message);
-        assert(m);
-
-        /* only accept org.freedesktop.systemd1.Agent from UID=0 */
-        r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
-        if (r < 0)
-                return r;
-
-        r = sd_bus_creds_get_euid(creds, &sender_uid);
-        if (r < 0 || sender_uid != 0)
-                return 0;
-
-        /* parse 'cgroup-empty' notification */
-        r = sd_bus_message_read(message, "s", &cgroup);
-        if (r < 0) {
-                bus_log_parse_error(r);
-                return 0;
-        }
-
-        s = hashmap_get(m->sessions, cgroup);
-
-        if (!s) {
-                log_warning("Session not found: %s", cgroup);
-                return 0;
-        }
-
-        session_finalize(s);
-        session_free(s);
-
-        return 0;
-}
-
 static int manager_connect_bus(Manager *m) {
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
         int r;
@@ -742,16 +641,6 @@ static int manager_connect_bus(Manager *m) {
         if (r < 0)
                 return log_error_errno(r, "Failed to add manager object vtable: %m");
 
-        /* elogind relies on signals from its release agent */
-        r = sd_bus_add_match(
-                        m->bus,
-                        NULL,
-                        "type='signal',"
-                        "interface='org.freedesktop.elogind.Agent',"
-                        "member='Released',"
-                        "path='/org/freedesktop/elogind/agent'",
-                        signal_agent_released, m);
-
         r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/login1/seat", "org.freedesktop.login1.Seat", seat_vtable, seat_object_find, m);
         if (r < 0)
                 return log_error_errno(r, "Failed to add seat object vtable: %m");
@@ -842,7 +731,12 @@ static int manager_connect_bus(Manager *m) {
         if (r < 0)
                 return log_error_errno(r, "Failed to attach bus to event loop: %m");
 
-        return 0;
+#if 1 /// elogind has to setup its release agent
+        elogind_bus_setup_system(m);
+        r = elogind_setup_cgroups_agent(m);
+#endif // 1
+
+        return r;
 }
 
 static int manager_vt_switch(sd_event_source *src, const struct signalfd_siginfo *si, void *data) {
index fc497f2..27b05fe 100644 (file)
@@ -32,7 +32,7 @@
 #RemoveIPC=yes
 #InhibitorsMax=8192
 #SessionsMax=8192
-#UserTasksMax=12288
+#UserTasksMax=33%
 
 [Sleep]
 #SuspendState=mem standby freeze
index 41b48ef..9be29ab 100644 (file)
@@ -29,7 +29,6 @@
 #include "sd-bus.h"
 #include "sd-event.h"
 
-#include "cgroup-util.h"
 #include "hashmap.h"
 #include "list.h"
 #include "set.h"
@@ -40,7 +39,14 @@ typedef struct Manager Manager;
 #include "logind-button.h"
 #include "logind-device.h"
 #include "logind-inhibit.h"
-#include "logind-sleep.h"
+
+/// Additional includes needed by elogind
+#include "cgroup-util.h"
+
+#if 1 /// elogind has to ident itself
+#define MANAGER_IS_SYSTEM(m) ((m)->is_system)
+#define MANAGER_IS_USER(m) (!((m)->is_system))
+#endif // 1
 
 struct Manager {
         sd_event *event;
@@ -78,8 +84,13 @@ struct Manager {
          * file system */
         int pin_cgroupfs_fd;
 
+        /* fd for handling cgroup socket if elogind is its own cgroups manager */
+        int cgroups_agent_fd;
+        sd_event_source *cgroups_agent_event_source;
+
         /* Flags */
         bool test_run:1;
+        bool is_system:1; /* true if elogind is its own cgroups manager */
 
         /* Data specific to the cgroup subsystem */
         CGroupMask cgroup_supported;