logind: add shutdown/suspend/idle inhibition framework

1 files changed, 365 insertions, 0 deletions

diff --git a/src/login/logind-inhibit.c b/src/login/logind-inhibit.c
new file mode 100644
index 0000000000..2f7a758e7c
--- /dev/null
+++ b/src/login/logind-inhibit.c
@@ -0,0 +1,365 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Lennart Poettering
+
+  systemd 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.
+
+  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/epoll.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include "util.h"
+#include "mkdir.h"
+
+#include "logind-inhibit.h"
+
+Inhibitor* inhibitor_new(Manager *m, const char* id) {
+        Inhibitor *i;
+
+        assert(m);
+
+        i = new0(Inhibitor, 1);
+        if (!i)
+                return NULL;
+
+        i->state_file = strappend("/run/systemd/inhibit/", id);
+        if (!i->state_file) {
+                free(i);
+                return NULL;
+        }
+
+        i->id = file_name_from_path(i->state_file);
+
+        if (hashmap_put(m->inhibitors, i->id, i) < 0) {
+                free(i->state_file);
+                free(i);
+                return NULL;
+        }
+
+        i->manager = m;
+        i->fifo_fd = -1;
+
+        return i;
+}
+
+void inhibitor_free(Inhibitor *i) {
+        assert(i);
+
+        free(i->who);
+        free(i->why);
+
+        hashmap_remove(i->manager->inhibitors, i->id);
+        inhibitor_remove_fifo(i);
+
+        if (i->state_file) {
+                unlink(i->state_file);
+                free(i->state_file);
+        }
+
+        free(i);
+}
+
+int inhibitor_save(Inhibitor *i) {
+        char *temp_path, *cc;
+        int r;
+        FILE *f;
+
+        assert(i);
+
+        r = safe_mkdir("/run/systemd/inhibit", 0755, 0, 0);
+        if (r < 0)
+                goto finish;
+
+        r = fopen_temporary(i->state_file, &f, &temp_path);
+        if (r < 0)
+                goto finish;
+
+        fchmod(fileno(f), 0644);
+
+        fprintf(f,
+                "# This is private data. Do not parse.\n"
+                "WHAT=%s\n"
+                "UID=%lu\n"
+                "PID=%lu\n",
+                inhibit_what_to_string(i->what),
+                (unsigned long) i->uid,
+                (unsigned long) i->pid);
+
+        if (i->who) {
+                cc = cescape(i->who);
+                if (!cc)
+                        r = -ENOMEM;
+                else {
+                        fprintf(f, "WHO=%s\n", cc);
+                        free(cc);
+                }
+        }
+
+        if (i->why) {
+                cc = cescape(i->why);
+                if (!cc)
+                        r = -ENOMEM;
+                else {
+                        fprintf(f, "WHY=%s\n", cc);
+                        free(cc);
+                }
+        }
+
+        if (i->fifo_path)
+                fprintf(f, "FIFO=%s\n", i->fifo_path);
+
+        fflush(f);
+
+        if (ferror(f) || rename(temp_path, i->state_file) < 0) {
+                r = -errno;
+                unlink(i->state_file);
+                unlink(temp_path);
+        }
+
+        fclose(f);
+        free(temp_path);
+
+finish:
+        if (r < 0)
+                log_error("Failed to save inhibit data for %s: %s", i->id, strerror(-r));
+
+        return r;
+}
+
+int inhibitor_start(Inhibitor *i) {
+        assert(i);
+
+        if (i->started)
+                return 0;
+
+        log_debug("Inhibitor %s (%s) pid=%lu uid=%lu started.",
+                  strna(i->who), strna(i->why),
+                  (unsigned long) i->pid, (unsigned long) i->uid);
+
+        inhibitor_save(i);
+
+        i->started = true;
+
+        manager_send_changed(i->manager, "Inhibited\0");
+
+        return 0;
+}
+
+int inhibitor_stop(Inhibitor *i) {
+        assert(i);
+
+        if (i->started)
+                log_debug("Inhibitor %s (%s) pid=%lu uid=%lu stopped.",
+                          strna(i->who), strna(i->why),
+                          (unsigned long) i->pid, (unsigned long) i->uid);
+
+        if (i->state_file)
+                unlink(i->state_file);
+
+        i->started = false;
+
+        manager_send_changed(i->manager, "Inhibited\0");
+
+        return 0;
+}
+
+int inhibitor_load(Inhibitor *i) {
+        InhibitWhat w;
+        int r;
+        char *cc,
+                *what = NULL,
+                *uid = NULL,
+                *pid = NULL,
+                *who = NULL,
+                *why = NULL;
+
+        r = parse_env_file(i->state_file, NEWLINE,
+                           "WHAT", &what,
+                           "UID", &uid,
+                           "PID", &pid,
+                           "WHO", &who,
+                           "WHY", &why,
+                           "FIFO", &i->fifo_path,
+                           NULL);
+        if (r < 0)
+                goto finish;
+
+        w = inhibit_what_from_string(what);
+        if (w >= 0)
+                i->what = w;
+
+        parse_uid(uid, &i->uid);
+        parse_pid(pid, &i->pid);
+
+        if (who) {
+                cc = cunescape(who);
+                if (!cc) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                free(i->who);
+                i->who = cc;
+        }
+
+        if (why) {
+                cc = cunescape(why);
+                if (!cc) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                free(i->why);
+                i->why = cc;
+        }
+
+        if (i->fifo_path) {
+                int fd;
+
+                fd = inhibitor_create_fifo(i);
+                if (fd >= 0)
+                        close_nointr_nofail(fd);
+        }
+
+finish:
+        free(what);
+        free(uid);
+        free(pid);
+        free(who);
+        free(why);
+
+        return r;
+}
+
+int inhibitor_create_fifo(Inhibitor *i) {
+        int r;
+
+        assert(i);
+
+        /* Create FIFO */
+        if (!i->fifo_path) {
+                r = safe_mkdir("/run/systemd/inhibit", 0755, 0, 0);
+                if (r < 0)
+                        return r;
+
+                if (asprintf(&i->fifo_path, "/run/systemd/inhibit/%s.ref", i->id) < 0)
+                        return -ENOMEM;
+
+                if (mkfifo(i->fifo_path, 0600) < 0 && errno != EEXIST)
+                        return -errno;
+        }
+
+        /* Open reading side */
+        if (i->fifo_fd < 0) {
+                struct epoll_event ev;
+
+                i->fifo_fd = open(i->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
+                if (i->fifo_fd < 0)
+                        return -errno;
+
+                r = hashmap_put(i->manager->inhibitor_fds, INT_TO_PTR(i->fifo_fd + 1), i);
+                if (r < 0)
+                        return r;
+
+                zero(ev);
+                ev.events = 0;
+                ev.data.u32 = FD_FIFO_BASE + i->fifo_fd;
+
+                if (epoll_ctl(i->manager->epoll_fd, EPOLL_CTL_ADD, i->fifo_fd, &ev) < 0)
+                        return -errno;
+        }
+
+        /* Open writing side */
+        r = open(i->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
+        if (r < 0)
+                return -errno;
+
+        return r;
+}
+
+void inhibitor_remove_fifo(Inhibitor *i) {
+        assert(i);
+
+        if (i->fifo_fd >= 0) {
+                assert_se(hashmap_remove(i->manager->inhibitor_fds, INT_TO_PTR(i->fifo_fd + 1)) == i);
+                assert_se(epoll_ctl(i->manager->epoll_fd, EPOLL_CTL_DEL, i->fifo_fd, NULL) == 0);
+                close_nointr_nofail(i->fifo_fd);
+                i->fifo_fd = -1;
+        }
+
+        if (i->fifo_path) {
+                unlink(i->fifo_path);
+                free(i->fifo_path);
+                i->fifo_path = NULL;
+        }
+}
+
+InhibitWhat manager_inhibit_what(Manager *m) {
+        Inhibitor *i;
+        Iterator j;
+        InhibitWhat what = 0;
+
+        assert(m);
+
+        HASHMAP_FOREACH(i, m->inhibitor_fds, j)
+                what |= i->what;
+
+        return what;
+}
+
+const char *inhibit_what_to_string(InhibitWhat w) {
+
+        static const char* const table[_INHIBIT_WHAT_MAX] = {
+                [0] = "",
+                [INHIBIT_SHUTDOWN] = "shutdown",
+                [INHIBIT_SUSPEND] = "suspend",
+                [INHIBIT_IDLE] = "idle",
+                [INHIBIT_SHUTDOWN|INHIBIT_SUSPEND] = "shutdown:suspend",
+                [INHIBIT_SHUTDOWN|INHIBIT_IDLE] = "shutdown:idle",
+                [INHIBIT_SHUTDOWN|INHIBIT_SUSPEND|INHIBIT_IDLE] = "shutdown:suspend:idle",
+                [INHIBIT_SUSPEND|INHIBIT_IDLE] = "suspend:idle"
+        };
+
+        if (w < 0 || w >= _INHIBIT_WHAT_MAX)
+                return NULL;
+
+        return table[w];
+}
+
+InhibitWhat inhibit_what_from_string(const char *s) {
+        InhibitWhat what = 0;
+        char *w, *state;
+        size_t l;
+
+        FOREACH_WORD_SEPARATOR(w, l, s, ":", state) {
+                if (l == 8 && strncmp(w, "shutdown", l) == 0)
+                        what |= INHIBIT_SHUTDOWN;
+                else if (l == 7 && strncmp(w, "suspend", l) == 0)
+                        what |= INHIBIT_SUSPEND;
+                else if (l == 4 && strncmp(w, "idle", l) == 0)
+                        what |= INHIBIT_IDLE;
+                else
+                        return _INHIBIT_WHAT_INVALID;
+        }
+
+        return what;
+
+}