src/login/logind-device.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2011 Lennart Poettering
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  21 #include <string.h>
  22
  23 #include "alloc-util.h"
  24 #include "logind-device.h"
  25 #include "util.h"
  26
  27 Device* device_new(Manager *m, const char *sysfs, bool master) {
  28         Device *d;
  29
  30         assert(m);
  31         assert(sysfs);
  32
  33         d = new0(Device, 1);
  34         if (!d)
  35                 return NULL;
  36
  37         d->sysfs = strdup(sysfs);
  38         if (!d->sysfs)
  39                 return mfree(d);
  40
  41         if (hashmap_put(m->devices, d->sysfs, d) < 0) {
  42                 free(d->sysfs);
  43                 return mfree(d);
  44         }
  45
  46         d->manager = m;
  47         d->master = master;
  48         dual_timestamp_get(&d->timestamp);
  49
  50         return d;
  51 }
  52
  53 static void device_detach(Device *d) {
  54         Seat *s;
  55         SessionDevice *sd;
  56
  57         assert(d);
  58
  59         if (!d->seat)
  60                 return;
  61
  62         while ((sd = d->session_devices))
  63                 session_device_free(sd);
  64
  65         s = d->seat;
  66         LIST_REMOVE(devices, d->seat->devices, d);
  67         d->seat = NULL;
  68
  69         if (!seat_has_master_device(s)) {
  70                 seat_add_to_gc_queue(s);
  71                 seat_send_changed(s, "CanGraphical", NULL);
  72         }
  73 }
  74
  75 void device_free(Device *d) {
  76         assert(d);
  77
  78         device_detach(d);
  79
  80         hashmap_remove(d->manager->devices, d->sysfs);
  81
  82         free(d->sysfs);
  83         free(d);
  84 }
  85
  86 void device_attach(Device *d, Seat *s) {
  87         Device *i;
  88         bool had_master;
  89
  90         assert(d);
  91         assert(s);
  92
  93         if (d->seat == s)
  94                 return;
  95
  96         if (d->seat)
  97                 device_detach(d);
  98
  99         d->seat = s;
 100         had_master = seat_has_master_device(s);
 101
 102         /* We keep the device list sorted by the "master" flag. That is, master
 103          * devices are at the front, other devices at the tail. As there is no
 104          * way to easily add devices at the list-tail, we need to iterate the
 105          * list to find the first non-master device when adding non-master
 106          * devices. We assume there is only a few (normally 1) master devices
 107          * per seat, so we iterate only a few times. */
 108
 109         if (d->master || !s->devices)
 110                 LIST_PREPEND(devices, s->devices, d);
 111         else {
 112                 LIST_FOREACH(devices, i, s->devices) {
 113                         if (!i->devices_next || !i->master) {
 114                                 LIST_INSERT_AFTER(devices, s->devices, i, d);
 115                                 break;
 116                         }
 117                 }
 118         }
 119
 120         if (!had_master && d->master)
 121                 seat_send_changed(s, "CanGraphical", NULL);
 122 }