device.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 #include <errno.h>
   4 #include <libudev.h>
   5
   6 #include "unit.h"
   7 #include "device.h"
   8 #include "strv.h"
   9 #include "log.h"
  10
  11 static void device_done(Unit *u) {
  12         Device *d = DEVICE(u);
  13
  14         assert(d);
  15         free(d->sysfs);
  16 }
  17
  18 static void device_dump(Unit *u, FILE *f, const char *prefix) {
  19
  20         static const char* const state_table[_DEVICE_STATE_MAX] = {
  21                 [DEVICE_DEAD] = "dead",
  22                 [DEVICE_AVAILABLE] = "available"
  23         };
  24
  25         Device *d = DEVICE(u);
  26
  27         assert(d);
  28
  29         fprintf(f,
  30                 "%sDevice State: %s\n"
  31                 "%sSysfs Path: %s\n",
  32                 prefix, state_table[d->state],
  33                 prefix, d->sysfs);
  34 }
  35
  36 static int device_add_escaped_name(Unit *u, const char *dn) {
  37         char *e;
  38         int r;
  39
  40         assert(u);
  41         assert(dn);
  42         assert(dn[0] == '/');
  43
  44         if (!(e = unit_name_escape_path(dn+1, ".device")))
  45                 return -ENOMEM;
  46
  47         r = unit_add_name(u, e);
  48         free(e);
  49
  50         if (r < 0 && r != -EEXIST)
  51                 return r;
  52
  53         return 0;
  54 }
  55
  56 static int device_process_device(Manager *m, struct udev_device *dev) {
  57         const char *dn, *names, *wants, *sysfs;
  58         Unit *u = NULL;
  59         int r;
  60         char *e, *w, *state;
  61         size_t l;
  62         bool delete;
  63         struct udev_list_entry *item = NULL, *first = NULL;
  64
  65         assert(m);
  66
  67         /* Check whether this entry is even relevant for us. */
  68         dn = udev_device_get_devnode(dev);
  69         names = udev_device_get_property_value(dev, "SYSTEMD_NAMES");
  70         wants = udev_device_get_property_value(dev, "SYSTEMD_WANTS");
  71
  72         if (!dn && !names && !wants)
  73                 return 0;
  74
  75         /* Ok, seems kinda interesting. Now, let's see if this one
  76          * already exists. */
  77
  78         if (!(sysfs = udev_device_get_syspath(dev)))
  79                 return -ENOMEM;
  80
  81         assert(sysfs[0] == '/');
  82         if (!(e = unit_name_escape_path(sysfs+1, ".device")))
  83                 return -ENOMEM;
  84
  85         if (!(u = manager_get_unit(m, e))) {
  86                 const char *model;
  87
  88                 delete = true;
  89
  90                 if (!(u = unit_new(m))) {
  91                         free(e);
  92                         return -ENOMEM;
  93                 }
  94
  95                 r = unit_add_name(u, e);
  96                 free(e);
  97
  98                 if (r < 0)
  99                         goto fail;
 100
 101                 if (!(DEVICE(u)->sysfs = strdup(sysfs))) {
 102                         r = -ENOMEM;
 103                         goto fail;
 104                 }
 105
 106                 if ((model = udev_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE")) ||
 107                      (model = udev_device_get_property_value(dev, "ID_MODEL")))
 108                         if (!(u->meta.description = strdup(model))) {
 109                                 r = -ENOMEM;
 110                                 goto fail;
 111                         }
 112
 113         } else {
 114                 delete = false;
 115                 free(e);
 116         }
 117
 118         if (dn)
 119                 if ((r = device_add_escaped_name(u, dn)) < 0)
 120                         goto fail;
 121
 122         first = udev_device_get_devlinks_list_entry(dev);
 123         udev_list_entry_foreach(item, first)
 124                 if ((r = device_add_escaped_name(u, udev_list_entry_get_name(item))) < 0)
 125                         goto fail;
 126
 127         if (names) {
 128                 FOREACH_WORD(w, l, names, state) {
 129                         if (!(e = strndup(w, l)))
 130                                 goto fail;
 131
 132                         r = unit_add_name(u, e);
 133                         free(e);
 134
 135                         if (r < 0 && r != -EEXIST)
 136                                 goto fail;
 137                 }
 138         }
 139
 140
 141         if (set_isempty(u->meta.names)) {
 142                 r = -EEXIST;
 143                 goto fail;
 144         }
 145
 146         if (wants) {
 147                 FOREACH_WORD(w, l, wants, state) {
 148                         if (!(e = strndup(w, l)))
 149                                 goto fail;
 150
 151                         r = unit_add_dependency_by_name(u, UNIT_WANTS, e);
 152                         free(e);
 153
 154                         if (r < 0)
 155                                 goto fail;
 156                 }
 157         }
 158
 159         unit_add_to_load_queue(u);
 160         return 0;
 161
 162 fail:
 163         if (delete && u)
 164                 unit_free(u);
 165         return r;
 166 }
 167
 168 static int device_process_path(Manager *m, const char *path) {
 169         int r;
 170         struct udev_device *dev;
 171
 172         assert(m);
 173         assert(path);
 174
 175         if (!(dev = udev_device_new_from_syspath(m->udev, path))) {
 176                 log_warning("Failed to get udev device object from udev for path %s.", path);
 177                 return -ENOMEM;
 178         }
 179
 180         r = device_process_device(m, dev);
 181         udev_device_unref(dev);
 182         return r;
 183 }
 184
 185 static void device_shutdown(Manager *m) {
 186         assert(m);
 187
 188         if (m->udev)
 189                 udev_unref(m->udev);
 190 }
 191
 192 static int device_enumerate(Manager *m) {
 193         int r;
 194         struct udev_enumerate *e = NULL;
 195         struct udev_list_entry *item = NULL, *first = NULL;
 196
 197         assert(m);
 198
 199         if (!(m->udev = udev_new()))
 200                 return -ENOMEM;
 201
 202         if (!(e = udev_enumerate_new(m->udev))) {
 203                 r = -ENOMEM;
 204                 goto fail;
 205         }
 206
 207         if (udev_enumerate_scan_devices(e) < 0) {
 208                 r = -EIO;
 209                 goto fail;
 210         }
 211
 212         first = udev_enumerate_get_list_entry(e);
 213         udev_list_entry_foreach(item, first)
 214                 device_process_path(m, udev_list_entry_get_name(item));
 215
 216         udev_enumerate_unref(e);
 217
 218         return 0;
 219
 220 fail:
 221         if (e)
 222                 udev_enumerate_unref(e);
 223
 224         device_shutdown(m);
 225         return r;
 226 }
 227
 228 static UnitActiveState device_active_state(Unit *u) {
 229         return DEVICE(u)->state == DEVICE_DEAD ? UNIT_INACTIVE : UNIT_ACTIVE;
 230 }
 231
 232 const UnitVTable device_vtable = {
 233         .suffix = ".device",
 234
 235         .init = unit_load_fragment_and_dropin,
 236         .done = device_done,
 237         .dump = device_dump,
 238
 239         .enumerate = device_enumerate,
 240         .shutdown = device_shutdown,
 241
 242         .active_state = device_active_state
 243 };